歷史

西漢歷史

楚漢之爭

前209年，秦末，由于政令愈發嚴苛，而最終爆發陳勝、吳廣「揭竿起義」的事件，先秦六國舊貴族也藉此時機紛紛複國。秦二世三年十月，楚分兵，拜宋義為上將軍，項羽為次將，范增為末將，率軍救趙；同時令沛公劉邦將碭郡兵西向攻秦。沛公先率楚軍北上收陳勝、項梁散卒，至東郡，與王離軍相遇。楚軍出擊秦軍，于杠里大破東郡尉與王離所率領的秦軍。宋義率楚軍行至安陽按兵不動， 前207年四月，楚國貴族後代項羽率領諸侯聯軍在鉅鹿之戰消滅王離、降章邯秦軍，同時劉邦北上先後開封之戰 白馬之戰 穎川之戰 洛陽之戰 武關之戰 蟯關、藍田之戰等戰役後滅秦進軍咸陽，而劉邦則入關推翻秦廷。。其後，項羽尊楚懷王為「義帝」，並自行分封天下（見《項羽十八諸侯列表》），封自己為「西楚霸王」，封劉邦為漢王。之後兩股勢力開始長達四年的楚漢戰爭。劉邦在蕭何、韓信、曹參、灌嬰、靳歙、周勃、酈食其、張良等人的協助下，最終在垓下之戰中擊敗項羽，於前202年在定陶登基正式稱帝，立國號「漢」，史稱西漢。

西漢開國

漢高祖劉邦登基後，採用叔孫通的建議，恢復禮法，設三公和九卿，任用蕭何為丞相，採取與民休息、清靜無為的黃老治術政策，鼓勵生產，輕徭薄賦。在政治上，則先分封異姓王、臧荼、彭越、英布等為王，以及一些功臣為列侯（詳見《西漢開國功臣封爵列表》）。

稱帝之後，異姓諸侯王勢大，因此漢初幾年對異姓王一一分別翦除，改封劉氏宗親為王，僅存長沙王吳臣。後劉邦與功臣刑白馬立盟誓：「非劉氏而王者，天下共擊之」，史稱「白馬之誓」。漢初政府官員基本上由大大小小的功臣充任，從而形成漢初「布衣卿相」的政治格局。

此時，由於秦末以來動亂多年，國力虛弱，漢高祖在平定異姓王韓王信的叛亂時雖三次野戰打敗冒頓。匈奴越過句注山逃跑，採取誘敵之計包圍劉邦，劉邦看出了端倪，派人前往打探情況，婁敬認為不可攻擊，但數萬漢軍已越過句注山追擊，劉邦不想打擊漢軍高漲的士氣，部署追擊，為了防止不測，派周勃南下攻打樓煩的三座城池，再跟主力會合，以備後援，後來劉邦被冒頓包圍在平城，劉邦堅守白登山，冒頓一時不能攻下，7日後周勃的軍隊趕到，攻打冒頓的包圍圈，為劉邦解圍，漢軍打敗匈奴，由於國力虛弱無法大規模反擊匈奴。從此以後，漢朝採用和親政策，以婚姻和財寶換取和平。據史料記載，前後一共送去10位宗室之女，即冒頓單于于前200年、前192年、前176年所收到的3位公主，老上單于于前174年、前162年所收到的2位公主，軍臣單于于前160年、前156年、前155年、前152年、前140年所收到的5位公主。

呂后專政

公元前196年，呂雉利用計謀於長樂宮鐘室將淮陰侯韓信殺死，滅三族。漢高祖去世後，太子劉盈繼位，是為漢惠帝。惠帝時年16歲，大權盡為太后呂雉（呂后）掌握。因漢高祖劉邦在世時，劉邦之寵姬戚夫人曾想謀立己子趙王如意為太子，結果遭到呂后和功臣們的強烈抵制而未能成功。劉邦去世後，呂后即毒死趙王劉如意。劉如意死後，呂后使人挖去戚夫人的雙眼、熏聾其耳、灌藥致啞、斷其手足，然後丟進茅房裏，命名為「人彘」，意即「如豬之人」。對其他劉氏諸王也多加殘害。又逼漢惠帝立自己年僅十歲的外甥女張嫣為后，史稱「孝惠張皇后」。但張氏實在年紀太小，一直無法懷孕。呂后于便設計張氏假裝懷孕，然後強取惠帝宮女所生之子，即前少帝，並偽稱為張皇后所生，又秘密處決了那個宮女，於是前少帝被立為皇太子。惠帝因呂后的殘暴而驚恐，數年後抑鬱病逝。前少帝逐漸成長，獲悉他的生母已為呂后所殺，公然表示長大後將會報複呂后。呂太后盛怒之下，便將他監禁于永巷中，並對外宣稱前少帝生病，大臣均不得見。後來更廢了前少帝，並暗中誅殺。五月，立恆山王劉山為皇帝改名劉弘，即後少帝。呂后臨朝稱制，開漢代皇太后臨朝稱制之先河，且數為後世所效仿。

呂后稱制，大封諸呂，並欲王諸呂，遭到時為右丞相的安國侯王陵堅決抵制。呂后偽升王陵為太傅，實欲奪其大權，然後大封呂氏外戚為諸侯王和列侯。呂后為了增加呂氏的籌碼，將呂氏之女與劉氏宗室聯姻，不僅擁有權力，也可以藉此監視劉氏子孫的一舉一動。並且呂氏外戚亦掌控禁軍，劉氏皇權遭到嚴重威脅。而朝中大臣多為隨漢高祖的開國功臣，他們表面上不敢反對呂后，但卻已經開始為此準備。呂后臨終時任命呂產為相國，先封呂祿為趙王，再任命他為上將軍，獨掌軍權。而以陳平、周勃為首之功臣派亦做好準備，並與劉氏皇族聯合。呂后一死，功臣派與皇族立即先發制人，發動政變，一舉誅平呂氏外戚，廢掉少帝劉弘，迎立漢高祖劉邦與薄氏之子代王劉恆為帝，是為漢文帝。

呂后掌權時代，惠帝七年，臨朝稱制八年，前後共15年。高層之權的奪權並沒有影響到國家的大政方針。呂后仍能忠實執行劉邦生前所定的休養生息、恢復民力的政策。相國（或丞相）之人選一如劉邦生前安排。蕭何去世後，曹參繼任，舉事無所更改，一遵蕭何約，力行清靜無為之政，史稱蕭規曹隨。除此之外，呂后秉政，繼續寬刑薄罰，如廢除「三族罪」、「挾書律」等秦朝惡法。對外政策上亦能理性冷靜處理，繼續「和親」政策，避免戰爭。這樣，呂后時期，國家經濟呈上升之勢，國力亦有很大增強。史稱：「孝惠皇帝、高祖之時，黎民得離戰國之苦，君臣俱欲休息乎無為，故惠帝拱己，高后女主稱制，政不出戶，天下晏然。刑罰罕用，罪人是稀。民務稼穡，衣食滋殖。」

文景之治

漢文帝之皇后竇太后非常喜歡《道德經》，尊崇道家，因此漢景帝與竇氏宗族都必須學習道家學說。漢文帝和兒子漢景帝在位期間，繼續秉持黃老無為的治國理念，奉行「無為無不為」的方針，實行輕徭薄賦、力行節儉的與民休息政策，恩威並施，以彌補秦末民變和楚漢戰爭的多年動亂帶來的巨大破壞，使人民負擔大大得到減輕，社會生產得以迅速恢復。通常認為文景之治的主要作為是漢文帝與漢景帝。實際上，竇太后在文景之治時代所起的作用也是舉足輕重的。《史記》卷三十《平準書》對文景之治作出仔細的描述，當中提到兩帝在位其間，並無重大事故，百姓人給家足。國庫累積上億的銅錢，因為久而不用，串錢的繩子都爛了。糧倉裡堆滿穀子，由於太多放不下而只能放在倉外，以致腐爛而不能食用。

文帝在位時，存在諸侯王國勢力過大及匈奴入侵中原等問題。文帝對待這些問題採取的是異常謹慎而且又有效的手法。對待諸侯王，文帝採取以德服人的態度，小錯不糾，在中央弱勢的時候成功的安撫住各地蠢蠢欲動的諸侯，為後來景帝處理七國之亂造就一批忠心耿耿的諸侯王和大臣。最重要的兩個大動作是：安撫吳王，使得吳王在最年富力強的時候沒有假借喪子之仇反叛；在齊王死後將齊國一分為七，既滿足齊王的兒子們稱王的需求，為自己贏得賢德之名，又消除最大的一個諸侯國齊國。假如文帝的謹慎穩重的做法被一直持續下去，漢朝也就不會發生後來的七國之亂，諸侯王問題亦有希望能夠和平解決。文帝二年（前178年）和十二年（前168年）分別兩次「除田租稅之半」，即是租率最終減為三十稅一（3.33%）。文帝十三年，還把土地稅完全免了。同時，對周邊敵對國家也不輕易出兵，維持和平，以免耗損國力。這就是輕徭薄賦的政策。文帝生活也十分節儉，宮室內車騎衣服沒有增添，衣不曳地，帷帳不施文繡，更下詔禁止郡國貢獻奇珍異物。因此，國家的開支有所節制，貴族官僚不敢奢侈無度，從而減輕人民的負擔。這就是休養生息的政策。文帝時，緹縈上文帝，痛陳肉刑的弊端，並願意代父贖罪，亦即後人熟悉的故事「緹縈救父」。文帝納言廢除肉刑，下詔廢除黥刑、劓刑、刖刑等刑罰，改用笞刑代替，並饒恕其父，可見文帝是寬容的一代賢君。

景帝即位不久，就採納晁錯的建議，削奪諸藩王的封地，引發各王的擔憂，而在景帝三年正月（zh-hans:公元; zh-hant:西元;前154年）爆發以「清君側」為名義的「七國之亂」，漢景帝因此腰斬了晁錯，以寄達到平息叛亂的目的。但是七國之亂並未因此緩和，景帝任用周亞夫出兵平叛，在三月即告弭平，各諸侯國的勢力因此極大削弱。七國之亂以後，景帝開始專心打理朝政，據說景帝十分樸素，仁厚愛民。除了平定七國之亂以外，從來沒有大規模用過兵，和匈奴的戰爭始終控制在一定的規模內，依然對匈奴採取和親政策。

在與匈奴和南越國（南粵）保持和平的同時，也在積蓄國力，透過馬復令等措施來積極備戰；此一時期史稱「文景之治」，是中國成為大一統帝國時代以來，第一次被傳統歷史學家讚譽的時期。

漢武盛世

景帝駕崩後，其子劉徹即位，是為漢武帝。武帝在位共五十四年，是清朝康熙皇帝以前以及漢朝在位最久的皇帝，也就是中國歷史上在位第三長的皇帝。在位期間（在位前141年—前87年）承上啟下，開創了漢武盛世，並採取一系列改革措施，銳意進取，使得西漢的政治、經濟及軍事大展新風貌，開創中國前所未見的波瀾盛世。可惜他好大喜功，在其政治生涯中留下了一大汙點。

在政治上，武帝加強皇權，建立年號「建元」，始開中國以皇帝年號紀年的先例，採納主父偃的建議，施行推恩令，削弱諸侯藩王的勢力，從此，諸侯藩王的勢力不再能夠對中央朝廷構成威脅；後又以諸侯獻上的黃金成色不純為由，取消百餘位列侯的爵位，即史書上所稱的「酎金失侯」事件。經此二次事件後，中央集權得到大大的加強。文化上，廢除過去以「黃老學說、無為而治」的治國思想，積極治國；並採納董仲舒「罷黜百家，獨尊儒術」的建議，使儒家思想從此逐步成為中國歷經二千年的「主流思想」。

對外關繫上，積極對付西漢的最大外患—匈奴。在此期間，先後出現衛青、霍去病、李廣、李陵、李廣利、公孫賀、公孫敖等傑出名將，經過武帝、昭帝、宣帝三朝數十年用兵後，終於徹底擊潰匈奴單于，使其「漠南無王庭」；又吞滅南越國，征討朝鮮，使漢朝成為當時的東方霸主。外交上，兩次派張騫出使西域，開闢絲綢之路，並先後以兩位公主劉細君、劉解憂和親西域大國烏孫，而達到離間西域和匈奴關係，進而聯絡西域的目的。

漢武帝晚年篤信巫術，聽信江充讒言，導致發生著名的「巫蠱之禍」，在這件事中，公孫敖、公孫賀、公孫敬聲、衛君孺（衛子夫之姐）、衛伉(衛青長子)、衛伐（衛青次子）、及太子劉據因而死亡。而皇后衛子夫也因過度傷心而自殺。

西漢經過多年對外戰爭，文景之治的積蓄耗費殆盡，經濟遭受巨大衝擊，國力也出現衰退的局面。為此，在巫蠱之禍後，漢武帝利用遠征軍失利的時機發表著名的「輪臺之詔」。辛德勇認為，輪台詔不是罪己詔，關于漢武帝罪己是資治通鑑的虛構，漢武帝死後並未改變西漢對外戰爭的基本國策。而田餘慶認為漢武帝晚期改弦易轍。為提振經濟，漢武帝將鑄幣、鹽鐵收歸中央管理，加強農業生產，實行和糴法，開鑿白渠，並創立均輸、平準政策，統購統銷，幹預物價，加強國家在經濟中扮演的角色。

昭宣中興

武帝去世後，鉤弋夫人（趙婕妤）之子，年僅八歲的劉弗陵即位，是為漢昭帝。漢昭帝登基之初，由上官桀、金日磾和霍光三人共同輔政。但是在元鳳元年（前80年），爆發元鳳政變，上官桀被殺，霍光從此大權獨攬。霍光延續武帝在位晚年的政策，對內休養生息，放寬鹽鐵專賣制度，提高儒生地位。昭帝死後，武帝孫昌邑王劉賀即位。他行為放縱（在位27天做出1127件荒唐的事，不排入帝序），密謀排除霍光，但反被霍光所廢。之後霍光又迎立劉病已(後改為劉詢)即位，是為漢宣帝。本始元年（前73年），霍光還政于宣帝。地節二年（前68年），霍光去世。此後宣帝將霍氏集團一網打盡。但是，宣帝繼續奉行霍光的治國路線，大力整頓吏治，勸民農桑，抑制兼併，降低國家在經濟中的角色。這段時期，漢朝不僅內政清明，而且對於匈奴繼續保持強勢，在漢宣帝神爵二年（前60年）設立西域都護以加強對西域三十六國所處地區的聯絡與控制。經過昭宣二帝的休養生息，國家經濟得以從武帝中期以來的衰頹困境下明顯恢復，並使漢帝國達到空前臻美的狀態，史稱「昭宣中興」。

王莽奪位

宣帝死後，漢元帝劉奭即位，西漢開始走向衰落。元帝「柔仁好儒」，對于社會秩序採取放縱態度，經常下令大赦，並且放棄了漢初以來遷徙關東豪強充實關中陵寢地區的制度，導致盜賊遍地，土地兼併日益嚴重，也致使皇權旁落，外戚與宦官勢力興起。他死後，成帝劉驁即位。漢成帝時漢成帝的舅舅、王鳳與許平君的堂弟、孝成許皇后的父親許嘉並立為大司馬車騎將軍。後來小許皇后失寵、趙飛燕趙合德姐妹崛起，漢成帝沒有男性後代，外戚王鳳、王莽（田齊後人）逐漸控制了政權，王氏兄弟四人和侄王莽相繼為大司馬大將軍。成帝死後，由定陶王之子哀帝劉欣即位，哀帝有「斷袖之癖」，終日與他寵信的董賢廝混相好，外戚王氏的權力一度受壓抑。此時國家已是一片末世之象，民間「再受命」說法四起。元壽二年（前1年）八月，哀帝去世。太皇太后王政君派王莽接替董賢成為大司馬，並迎接中山王劉衎即位，是為漢平帝，改元元始。但是，劉衎已淪為王莽的傀儡。五年後，王莽毒死僅14歲的平帝，並立劉嬰為太子，號「孺子」，自己擔任「假皇帝」，初始元年十二月朔（9年1月15日），王莽正式稱帝，以劉嬰為定安公，建立新朝。

東漢歷史

光武中興

新莽天鳳五年（17年）綠林起義爆發，23年，僅十五年的新莽政權在赤眉、綠林民變下滅亡。同年2月，綠林軍擁立漢宗室劉玄作皇帝，恢復漢的國號，年號更始。25年赤眉軍向城陽景王劉章占卜，立景王後人劉盆子為帝，隨後擊敗綠林軍，更始帝劉玄向赤眉軍投降。通常劉玄被認為是西漢最後一位皇帝，但也有認為是孺子嬰才是西漢最後一位皇帝，原因是他被王莽篡位。若把一代而亡的新朝計入漢代歷史，那劉玄可算是西漢最後一位皇帝，因為劉秀建立的是新的劉氏宗室政權。

漢更始三年（25年）六月，原本服從更始帝的漢朝宗室劉秀在鄗縣（今河北高邑東南）之南即皇帝位，是為光武帝，滅劉盆子，仍沿用漢的國號，以這一年為建武元年，定都雒陽，史稱東漢。即位後，于37年終于消滅赤眉、隗囂、公孫述等割據勢力，統一全國。

漢光武帝廢除王莽時的弊政，建武二年（26年），光武帝下令整頓吏治，設尚書六人分掌國家大事，進一步削弱三公（太尉、司徒、司空）的權力，加強中央集權；同時清查土地、新定稅制、振興農業，使人民生活逐步穩定下來；另外提倡儒術，建立太學，設置五經博士，與尊儒並行的便是表彰氣節，因此士大夫爭相以名節為目標，為淳美的政教，奠下基礎；對匈奴等外部勢力實行防禦的策略，對外戚嚴加限制，史稱光武中興。但由於分封土地，也造成土地兼併情況日益嚴重，地方豪強勢力興起，為東漢的最終滅亡埋下隱患。

明章之治

漢明帝和漢章帝在位期間，東漢進入全盛時期，史稱「明章之治」，此時推行的是儒家，與西漢的「文景之治」同為各時期的鼎盛。期間，竇固以班超出使西域，班超在西域長駐三四十年，不僅善於使用武力威懾各國，更善於運用外交手段去聯絡距離較遠的國家。但匈奴人亦同樣在開展類似的行動，推翻各國親漢的政權，再與新政權結盟。雙方不斷地反覆攻防，一直到20年後，班超之子班勇才完全掌控西域。章和二年（88年）十月，車騎將軍竇憲領軍出塞，擊破北匈奴，登燕然山，令班固作銘命，史稱燕然勒石。二年後，永元三年（91年）竇憲派兵再次出擊，出塞五千里進攻金微山，大破北匈奴單于主力，斬名王以下五千餘人，俘虜北單于皇太后，北單于倉皇逃竄不知所終，從此掃除數百年來匈奴對漢朝北方邊境的威脅，漢朝國勢也再一次到達漢武帝時期的鼎盛；佛教也在此時傳入中國。但是在章帝後期，外戚竇氏日益跋扈，揭開東漢後期外戚與宦官兩股勢力爭鬥的序曲。

戚宦爭權

88年，年僅卅一歲的漢章帝突然駕崩，時僅十歲的太子劉肇即位，是為漢和帝，他即位伊始，實際上朝政都由竇皇后操縱，國家政治日益腐敗。竇氏的跋扈引發和帝的不滿，不久年僅14歲的和帝就抓捕外戚竇憲，外戚勢力開始衰弱，和帝信用宦官，從此東漢的政治淪為外戚和宦官兩股勢力的爭鬥。不過，和帝仍然在政事上非常勤奮，不失為英明之主。元興元年冬十二月，年僅廿七歲的和帝病逝。出生僅百日的少子劉隆即位，是為殤帝。殤帝僅在位8個月就駕崩。接替即位的是清河王劉慶之子安帝劉祜。他即位早期由太后鄧綏臨朝理政。鄧太后勤儉節約，任用賢良，同時對自己家族的勢力有所限制，卻也對宦官勢力縱容。建光元年（121年），鄧太后逝世，安帝親政，將鄧氏家族誅殺殆盡。安帝依賴外戚宋氏和閻氏以及宦官的力量。聽信奸臣，肆意無忌，朝政昏庸不堪，東漢快速衰落。延光四年三月，漢安帝在南巡途中死在葉城。外戚閻氏秘不發喪，擁立漢章帝之孫濟北王劉壽之子劉懿，史稱漢少帝，其在位僅200餘日就病死。少帝死後，閻氏家族密謀再立傀儡，被中常侍孫程擊破，閻氏家族被誅殺。孫程迎立濟陰王劉保，是為漢順帝。在順帝執政早期，宦官勢力膨脹，卻引發社會各界的反彈。陽嘉元年（132年），貴人梁妠立為皇后，從此梁氏外戚勢力開始崛起，梁妠的兄弟梁冀被任命為大將軍。漢安二年（143年）八月，順帝病死，太子劉炳即位，是為沖帝，即位時年僅2歲，由梁太后臨朝執政。永嘉元年（145年）正月初六，劉炳駕崩，年僅三歲。正月廿五日，梁冀擁立劉纘即位，是為質帝。質帝非常聰穎，稱梁冀為「跋扈將軍」，結果不久質帝就被毒殺。

本初元年閏六月初七日，大將軍梁冀擁立漢章帝之孫劉志即位，是為漢桓帝。桓帝年少，因此繼續由梁太后臨朝執政。桓帝即位之初，朝政由梁冀把持。桓帝對他暗中也頗為不滿，延熹二年八月初十，桓帝派兵士包圍梁宅，梁冀與妻子雙雙自殺，梁氏外戚勢力土崩瓦解。宦官成為新的權力中心。單超、徐璜、具瑗、左悺、唐衡五人被封為縣侯；單超食邑兩萬戶，後又封為車騎將軍，其他四人各一萬戶，世稱五侯。五侯貪婪放縱，終致在延熹九年（166年）引發第一次黨錮之禍。永康元年十二月廿八日（168年），漢桓帝駕崩。桓帝沒有留下子嗣，由河間王劉開的曾孫劉宏繼位，是為漢靈帝。靈帝即位之初，就引發以竇太后、竇武為首的外戚勢力和以曹節、王甫為首的宦官勢力的激烈權力鬥爭。宦官成功發動政變，殺死竇武。外戚勢力被削弱。宦官隨後製造第二次黨錮之禍。而靈帝本人驕奢淫逸，為填補財政公開賣官，朝政腐敗。

大亂國崩

數十年的政爭，長時間的羌亂以及天災動搖漢朝的民生，終於在184年爆發由太平道教主張角引發的黃巾之亂，黃巾軍以「蒼天已死，黃天當立；歲在甲子，天下大吉」號召數十萬民眾參與，雖然叛亂不久即告平定，但是東漢朝廷經此一役已實力大減,之後相繼爆發北宮伯玉之亂和張舉、張純叛亂。中央朝廷為了儘快平叛，又將軍政權力下放給各州的州牧。劉昭認為設立州牧是導致天下大亂的原因。

漢靈帝死後，外戚大將軍何進和宦官雙雙火併同時死亡，終於結束戚宦之爭。但董卓掌權後，廢少帝劉辯為弘農王，改立陳留王劉協。此舉引發關東州郡背叛中央，最終演變成東漢末年軍閥割據一方、群雄逐鹿的局面。董卓為了躲避關東聯軍，焚毀首都雒陽並遷都長安。董卓被呂布誅殺後，經過幾年混戰，出現把持朝廷的曹操、位于河北的袁紹、位于淮南的袁術、位于江東的孫策、位于荊州的劉表、位于益州的劉焉等勢力。其中曹操「挾天子以令諸侯」，架空漢室權力，消滅各路割據勢力，並在官渡之戰中消滅最強大的敵人袁紹軍隊的主力，基本統一北方。

漢獻帝建安十三年(208年），罷三公官，複置丞相，曹操任丞相，獨攬大權。曹操揮軍南征，卻在赤壁之戰中被孫權、劉備聯軍擊敗，曹操被迫回北方，鞏固中原。不久劉備以荊州為根本，進占益州，曹劉孫三分天下之勢開始形成。而在這段期間，漢獻帝只是一個傀儡皇帝，真正實權掌握在曹操手中。曹操先是晉位為魏公，不久又晉位魏王。建安二十一年（216年），漢獻帝不再頒下詔書，漢皇帝向臣下發布詔書的權力被剝奪。漢至此已名存實亡。

建安25年（220年）春正月庚子，曹操去世，其世子曹丕繼任漢丞相，襲封魏王。同年漢魏禪代。221年，劉備稱帝。江東孫權雖向魏稱臣，內政外交皆自主，幾年後孫權亦稱帝，國號吳，三國時代正式開始。曹丕代漢後，漢朝宗室遭到曹魏禁錮。這一措施直到西晉泰始二年（266年）才被廢除。

季漢歷史

建安25年（220年）十一月，曹丕迫漢獻帝「禪讓」帝位，東漢結束。而曹丕代漢建立魏後，割據益州的漢朝宗室劉備隨即稱帝，宣布繼承漢朝法統，史稱蜀漢。諸葛亮主政期間，繼承劉備遺志發動五次北伐，期望攻佔隴西、克復中原，然而均遭到魏軍阻擋而未能有進一步的進展。直至公元263年，曹魏攻入蜀地，漢後主劉禪投降，蜀漢亡，歷二帝統治，共42年。

疆域

漢初，因秦末民變和楚漢戰爭致使國力虛弱，只得退讓防守。河南地區在秦末民變爆發時為匈奴占領。期間南越（南粵國），閩越（閩越國），黔中地區亦先後獨立。國土大幅減縮。

文景之治後，漢武帝時期，武功鼎盛，國土大幅擴展。元朔二年（前127年），衛青北擊匈奴，收復河南地、隴西、北地、上郡的北部，置朔方、五原二郡。雲中、雁門二郡的北界也向外擴展。西漢的北部疆界至此推到河套，陰山以北。元狩二年（前121年），漢將霍去病出隴西擊滅居於河西走廊的匈奴部落，以其地設酒泉郡。後又分割為張掖、敦煌、武威三郡。連同在湟水流域設置的金城郡，合為五郡，開始對西域的控制。建元三年（前138年），東甌迫于閩越王的威脅，舉國內遷到今江淮流域。元封元年（前110年），漢軍又平定閩越國，其地劃入會稽郡。元鼎六年（前111年），漢軍平南越國，又佔有海南島，在該地設十郡。在西南方向，漢軍征服諸國，邊界推移到雲南哀牢山和高黎貢山。元封二年-元封三年（前109年—前108年），漢軍在東北地區平定衛氏朝鮮，設置遼東四郡。邊疆形勢蔚為改觀。

新莽末年，疆域萎縮。東北撤銷真番、臨屯二郡。西南地區由七郡變成五郡，並且放棄海南島上的珠崖、儋耳二郡。光武中興後形勢得到改觀，版圖基本恢復。東漢末期，中原戰亂不斷。曹操放棄定襄、雲中、五原、朔方、上郡、北地六郡。河套、陝北、晉西北、河北北部地方先後放棄。高句麗與林邑兩國蠶食東北及南方國土。只有西南地區擴展至大盈江一帶，其中益州郡、牂牁郡、永昌郡，與西南滇王（前278年—115年）、夜郎王（直至前27年）、哀牢王（直至76年）及鉤町王共同並存。

在漢朝最大「領土」範圍內：東北的鮮卑、北邊的匈奴（漢朝打敗了匈奴）、中亞（漢攻大宛之戰、郅支圍城戰）、貴霜（漢朝打敗了貴霜）、青海西藏的羌人都是附屬國。漢朝打敗了匈奴後，漢朝在現代西伯利亞以及北極圈地區修建了阿巴坎遺址、燕然勒石等建築。

西域在漢朝早期是指南疆一帶，後來擴展到天山以北和中亞東部。西漢中早期，西域地區為匈奴所控制， 隨後武帝征服西域，西域成為漢朝的領土。

漢武帝時期，于建元三年（前138年）派張騫出使大月氏以聯合夾擊匈奴。張騫在路上一度被匈奴扣押，並在匈奴娶妻，十餘年後逃出，經大宛等國到大月氏，但未能取得夾擊匈奴的答復。後來張騫東返，又被匈奴扣押。直到元朔三年（前120年）才返回長安，回來時只剩他和隨從堂邑父兩人，他的匈奴妻子也一併來到長安。

元狩四年（前119年），漢武帝第二次派張騫出使西域，約烏孫共擊匈奴。雖然張騫未能說服烏孫國王夾擊匈奴，但是張騫卻與其使節先後遊歷大宛等國，後來亦由各國使節陪同，返回長安，從此以後，漢朝與匈奴反復在西域地區爭奪。元封六年（前105年），漢武帝以細君公主與烏孫和親。細君死後，漢又在太初四年（前101年）以解憂公主續嫁。同年，漢朝大破大宛，西域南道各國都轉投漢朝。漢武帝在烏壘設使者校尉，又在渠犁屯田。

到宣帝神爵二年（前60年），漢又驅逐匈奴駐在西域的僮僕都尉，控制西域北道，設立西域都護，總管西域事務，還在烏孫國都赤谷一帶屯田。元帝時，又增戊己校尉，在車師前王庭屯田。西漢末年，西域分為五十五國。

王莽時期，貶去其王號，降為侯，西域與漢關係趨緊，匈奴勢力再入。

東漢明帝初年以後，漢朝又恢復同西域的聯繫，並于永平十六年派將軍竇固入伊吾廬屯田駐兵，次年在烏壘設西域都護，派班超負責西域事務。永元九年（97年），班超派甘英出使大秦(羅馬帝國)。甘英經條支、安息等國，到大秦西界望海而還。

隨著西域局勢的逐步趨于穩定，商旅往來日益頻繁，絲綢之路在西漢後期形成。這也是世界歷史上最重要的商道之一。漢朝遣使者至安息、奄蔡、條支和身毒等國，一年多則十餘批，少則五六批，攜帶金幣帛等物品，需要至少兩三年，甚至八九年才能返回長安。中國運往西方的物產以絲綢、鐵器和漆器為主；而良馬、駱駝、香料、葡萄、石榴、苜蓿、胡麻、黃瓜、胡豆和胡桃等也源源不斷進入中國。

季漢主要佔領益州，共分為二十二郡，擁有一百三十一個縣國，劉備於建安十三年（208年）赤壁之戰後始得荊州的南郡部分及長沙、武陵等荊南4郡。建安十九年（214年）入蜀取得益州，明年與孫權議定平分荊州，219年劉備於漢中之戰打敗曹操得漢中郡。至建安二十四年（219年）時，計此時共轄有2州21郡1屬國。同年孫吳擊取荊州而喪失南郡、武陵郡、零陵郡3郡，諸葛亮北伐曹魏取得武都郡、陰平郡2郡，分割設置數郡。季漢滅亡以前，計轄有1州22郡。

政治體制

西漢前期的中央行政制度早期仿效秦朝實行三公九卿制，丞相、太尉、御史大夫稱三公，丞相管行政，是文官首長；太尉管軍事，是武官首長；御史大夫為副相掌監察，輔助丞相掌管政治事物。而在西漢，還有一條不成文的規定，即必須做御史大夫後才能做丞相。而在御史大夫之下，還設有御史中丞，掌管宮內事務。九卿則是太常（掌祭祀鬼神，兼掌教育事宜）、光祿勛（掌宮殿門房及皇帝侍衛隨從，兼掌州郡所薦三署郎人選之考選銓敘等人事事務）、衛尉（掌宮城衛兵）、太僕（掌車馬，兼掌全國牧政及驛站）、廷尉（掌法律審判）、大鴻臚（掌禮賓，兼掌外國及屬國交往）、宗正（掌宗室族譜及諸侯王公主等督訓）、大司農（掌全國經濟及財政用度）、少府（掌皇室財政，兼掌官營手工業作坊）。另外又有將作大匠（掌國家工程營繕）、執金吾（掌京師治安）、大長秋（協助皇后管理後宮），與九卿並稱「十二卿」。

漢武帝時期，皇權開始大幅膨脹，為壓制位高權重的丞相，內廷尚書令的地位大幅抬升。漢武帝將身邊重臣如嚴安、主父偃、朱買臣等為郎加以侍中，與尚書令共議軍國大事，組成中朝。原以宰相為首的三公九卿組成外朝。

綏和元年，漢成帝時改御史大夫為大司空，元壽二年，漢哀帝把丞相改稱大司徒，東漢時改稱司徒，負責掌理教化，東漢光武帝時，三公權力再次大幅被削弱，尚書臺權力得到提升。東漢早期的三公是司徒、司空和太尉，三公職位雖高，但其權力不複西漢之巨，僅餘每年考核天下州郡人民、土木、兵馬之政及分督九卿的督察權，政事綜理之責內移至禁中尚書台。尚書臺掌管全國政事，直接對皇帝負責。尚書臺設尚書令一人，為其主管長官；尚書僕射一人，為尚書令之副；左右丞各一人，為令、僕之佐。尚書令原分四曹，後增至六曹，每曹有尚書一人，侍郎六人。同時，東漢政府還設立三套監察機構，分別是中央的御史臺、兼具京官和地方官身份的司隸校尉與地方的州刺史。光武帝同時設立中常侍等宦官職務。一系列的措施大力削弱的三公的權力，尚書則權高位低，同時也為之後的宦官亂政埋下隱憂。

漢獻帝建安十三年，曹操掌控下的朝政下令廢除三公制，恢復漢初舊制，複設丞相，由曹操出任，軍國大事一由丞相統任。

行政區劃

西漢初，劉邦封異姓王七人。但由於對功臣的猜忌，不久又相繼削除，同時大封同姓諸侯，這些王國「大者或五六郡，連城數十，置百官宮觀，譖于天子」。地方王國勢力的強大導致中央政府所實際控制的區域萎縮。呂后時期，增加外戚諸侯王。到文帝時期又紛紛剷除，增加劉氏諸侯王。但是地方王國勢力的膨脹已經對中央政府構成嚴重威脅。文帝接受賈誼的建議，用分地的方法削弱諸侯的勢力。景帝即位後採納晁錯的建議，直接縮減王國的封地，引發諸侯王的強烈反彈，導致吳楚七國之亂爆發，但未幾就宣告失敗。武帝後，採納主父偃的建議，推行推恩令，規定諸侯王位由嫡子即位，而餘子皆分一縣或一鄉的土地。因此王國不斷縮小，漢郡不斷擴大，加上邊郡的開擴，漢朝中央政府對地方的控制力日益加強。同時，政府將大量面積較大郡予以分割。到平帝元始二年，共有郡國103個，轄縣、侯國、公主沐邑、道（少數民族聚居地）等縣級政區1587個。

「州」作為行政區劃，在西漢時期萌芽，到東漢宣告形成。武帝元封五年（前106年），始在郡之上又設十三行部，每部派一刺史，每個行部管轄若干郡（國）。但此時的行部是監察區，還不是真正意義上的行政區。東漢末年，地方多事。靈帝中平五年（189年），朝廷選重臣出任刺史，稱州牧，掌一州軍民。州從監察區變為行政區。至此，中國地方行政由原本的郡縣兩級制度變為州郡縣三級制。

十三個州部為：司隸校尉部（治雒陽）、徐州刺史部（治剡縣）、青州刺史部（治臨淄）、豫州刺史部（治譙縣）、冀州刺史部（治高邑）、并州刺史部（治晉陽）、幽州刺史部（治薊縣）、兗州刺史部（治昌邑）、涼州刺史部（治隴縣）、益州刺史部（治雒縣）、荊州刺史部（治漢壽）、揚州刺史部（治歷陽）和交州刺史部（治龍編）。獻帝興平元年（194年），又分涼州置雍州刺史部。則至漢亡，全國有十四州。

教育

漢承秦制，於諸子百家各立博士，統屬於太常，秩比六百石，其數多至數十人，數量多達數十人。但漢初朝廷所崇信的學術，黃老之外，便是申韓法家學說，對於儒家思想並不重視。到文帝時的賈誼，儒家思想才逐漸興起。武帝建元五年（前136年），增置五經博士，形成儒家獨大的局面。其後武帝又應公孫弘、董仲舒之請，於元朔五年（前124年）為五經博士置弟子員五十人，以受經術，期限為一年。弟子員的來源，主要選自民間十八歲以上的子弟，此外各郡具低級官吏品學兼優者，也可擔任弟子。畢業後，能通一經以上的可補「文學掌故」，等第高的可充任郎官，但只限於白身受業者。地方官吏出身的，則多派充九卿、列卿或郡太守的屬官。

宣帝時，五經博士增至十二人；王莽時，增設樂經，共為六經，每經設博士五人。弟子員也代有增加，昭帝時已滿百人，宣帝末至二百人，元帝時千人，到成帝時多至三千人。從太學的大量擴充，顯示西漢儒學教育的日益發展與儒家政治勢力的日益膨脹。東漢光武帝也於建武五年設學於京師，置博士十四人。太學生更不斷增加，質帝時，太學生已多至三萬人。

察舉制度

漢代察舉制度可分為兩類：一是詔舉，當國家有特殊需要時，下詔命官吏推舉人才。二是孝廉之舉，是由郡國按時向中央保薦當地的人才。薦舉為主，考試為輔，是兩漢察舉制的基本特點。

高祖曾於十一年（前196年），下詔徵求賢才，此舉開漢代選舉制的先河。其後文帝二年（前178年），曾下詔命「二三執政」舉「賢良方正、能直言極誎者」。至十五年（前165年），再度詔舉上項人才，保舉者的範圍則擴大到侯王、公卿和郡守，由皇帝親自策問，漢的選舉制自此開始普遍推行。其後武、昭、宣等朝，也曾屢次詔舉人才，都以賢良為主。西漢的名臣鼂錯、董仲舒、公孫弘等都以賢良入朝為官。漢代詔舉，除賢良外，尚有「文學高第」、「茂材異等」、「孝悌敦厚」、「勇猛知兵法」、「明當之務、習先聖之術」、「明陰陽災異」等名目，被舉者大抵為現任官吏。東漢時，詔舉由特舉變為歲舉，又稱茂材之舉。選舉的標準有四：即德行高超，經明行修，明曉法律和剛毅多略。每年由光祿勳、御史、司隸校尉及各州剌史等實責推舉。推行薦舉、察舉等方法的結果是門閥制度的大大發展，大量士族世家出現，與外戚、宦官形成東漢時期的三大勢力，基本壟斷國家政治。

漢朝的選舉制度是察舉制，以地方推薦為主，考試為輔，考試與推薦相輔而行。推薦過後是還要經過考試覆核；覆核合格後才能量才錄用。無論是特舉賢良方正，還是歲舉孝廉、茂才，均須經過中央覆試。漢代察舉制下的考試，在西漢時並不占主導地位，考試只是區分人才高下，授官大小的參考 ，這與後世以考試為主、以推薦為輔的科舉制截然不同。至東漢時，為糾正察舉薦人之濫，開始注重考試，形成察舉與考試相結合的選士制度，而且考試成份日益增加。在推薦基礎上加強考試，這是漢代察舉制發展的新趨勢。薦舉為主，考試為輔，是兩漢察舉制的基本特點。

法律

漢朝的法律是律、令、科、比四種。律是有系統的成文法律，具有傳統性；令，則是君主視需要隨時頒布的法律，與律具有相同的效力；比，或稱決事比及法比，是無成法可引用時用來比類決事的法律。漢律最早是蕭何制定的《九章律》，後來加上叔孫通《傍章》十八篇，張湯《越宮律》二十七篇，還有趙禹《朝律》六篇。漢律到武帝時期便已完備，但也由於法條過多，產生判決不公的情況發生，亦難免有自相矛盾之處，給予官吏做壞事的機會，昭帝以後的幾位皇帝，雖然有心改善，但始終沒有徹底執行。

西漢中期以後，儒學開始興盛，學者論法，多主張以德為主，以刑為輔。到了東漢時期，光武、明帝，雖然提倡儒術，仍然崇尚法制。章帝時，採納陳寵的建議，除去嚴酷的法律五十幾條。和帝後，外戚與宦臣，輪流把持朝政，他們一向違法亂紀，視法典於無物，法家的儒化，使東漢政治趨於迂緩，喪失西漢盛時發揚蹈厲的政治精神，儒家雖然興盛，卻對國事幫助不大，這種情況維持至東漢結束為止，獻帝時，曹操當國，用法尚嚴，命應劭刪定律令，作《漢儀》二百八十篇，雖然一度走向法治，但東漢不久被曹丕篡位而滅亡。

軍事制度

徵兵制

漢朝早期實行徵兵制度，男子廿三歲起至五十六歲之間，服役兩年。一年在地方服役，名為正卒；另一年戍守邊郡，叫做戍卒。正卒在本郡服役，劃分兵種，加以訓練。屯戍各分為兩種：在京城或王國都城屯戍的稱「衛士」，在邊郡屯戍的稱「戍卒」。服役期滿後，役男即可返鄉，不過仍有隨時應召服役的義務。兵役之外，還有繇役，即每年為郡縣政府服力役一月，服役者稱「更卒」，同樣也是五十六歲免役。

京師的駐軍分為兩支，一支為南軍，守衛宮城和官署，另一支為北軍，屯駐於三輔地區保衛首都其他地區。它們名稱的來源，是漢的長樂宮、未央宮等宮，都在長安城的南部，故宮廷衛軍集中於城南，守城軍隊的重心則在城北，因此有南北軍之稱。所謂衛士，即是指南軍士兵，由三輔以外的各郡役男輪番充任。但衛士是有經過選拔的，並非所有的役男都當衛士，不充衛士的則當戍卒。北軍的士兵，則由三輔的役男輪流擔任，可能即是服正卒役。至於王國的衛士，則只在本國首都服役，不須屯戍京師。屯邊的戍卒，大都是關東人，此外尚有少數當地人；他們在邊塞城堡中，擔任守望的工作。

服正卒役的役男，由各縣集中於郡，劃分兵種，給予訓練。當時的兵種，主要有四種，即步卒、材官（精選的步卒），騎士、樓船士（水兵）。兵種的確定，皆依照當地的環境來做為標準。如西北產馬，則當地役男多編為騎士；平原及山地區（如巴、蜀、三河、潁川諸郡）的役男，則多編為步卒和材官；東海沿海及江湖附近地區（如廬江、丹陽、會稽等郡）的役男，則多編為樓船士。此外還有一種車士，多用於喪儀。各郡的正卒統屬於太守，而由都尉指揮監督，每年八月，由太守，都尉會同各縣令長丞尉一同檢閱，評定高下，名曰「都試」。都試的科目，以射為主，並加試其他技術。靠水的地方，則作水師演習；邊郡地方，則由太守率領馬隊巡行塞障。正國的正卒，則統屬於相，而由中尉率領。

漢代雖沒有固定的免役法，但也有若干免役的規定，由皇帝隨時以詔令頒行，大致上可分為四類：一是有政治地位的人，可以免役。惠帝時，曾下詔規定官吏秩六百石以上與父母妻子同居的，或曾做過將軍，都尉、二千石的，都可免役。此外，如宗室、關內侯，也曾數見於詔令。二是用以獎勵才德。惠帝時，曾下詔免除「孝悌力田」者的免役。元帝時，能通一經的儒者也可免役。三是有功的人，可以免役。如高祖規定，凡曾隨他入蜀漢定三秦的二千石吏，可世世免役；跟他參加平城之役的吏卒，可終身免役。宣帝時，也曾詔准霍光的後代免役。四是特殊情況下的免役。如人民九十歲以上只有一子，或是身材短小與染有疾病者，均可免役。

編制與調發

漢朝軍隊的編制，可分為三項：一是京師駐軍及中央設立的地方常駐軍隊的編制，二是地方郡兵以及邊郡亭障的組織，三是戰時的統率系統。

京師駐軍有南北軍之分，其任務也不相同，南軍由衛尉統領，守衛宮城。官城以內各殿舍的守衛，則以衛郎擔，由郎中令統領。衛郎雖屬南軍系統，但其份子並非從各地的役男中抽調而來，而多半由二千石以上大官的子弟，有軍官的良家子，郡國推舉的孝廉的博士弟子員等來充任，此外還有不少富人子弟。這個集團可以說是皇帝最親信的衛隊，也是未來將相大臣的儲備所。武帝時，於南軍增置羽林、期門等兵，為皇帝的隨從護衛，由光祿勳統領。

北軍由中尉統領，它的職責是拱衛都城，維持京師的治安。武帝時，改中尉為執金吾，並增置八校尉（中壘、越騎、步兵、長水、射聲、屯騎、胡騎、虎賁）及城門校尉，於是北軍大幅擴充，東漢分北軍為五校，卽屯騎、越騎、步兵、長水、射聲，各由校尉率領；並另設城門校尉。

正南北兩軍原各有兩萬人，武帝時期各減為萬人。京師沒有長期駐紮的軍隊，正卒一年一輪換。同時另外組織三支侍從軍（期門、羽林和羽林孤兒）。元鼎六年（前111年），又成立八支禁衛軍，每支有士卒約七百人，由八個校尉率領，因稱「八校尉」。這是中國歷史上募兵制的開始。到東漢光武帝時期，軍權進一步集中到中央。東漢時的南軍，按編制衛尉以下共有官長公車司馬令，衛士令、都候、宮掖門司馬及丞、尉等十九人，員吏二百九十九人，衛士二千五百零七人。北軍五校則有官長校尉五人，司馬六人，員吏六百十四人，士兵三千五百三十六人。西漢南北軍的士兵，是按兵役法自各地徵調而來，東漢則是招募來的。南北兩軍因是首都衛戍部隊，都不負野戰勤務。但從武帝起，時有以京兵遠征的事，東漢因行募兵制，民不知兵，一遇有事，多以京兵出戰。

東漢和帝以後，宦官權勢日大，至靈帝時，更擁有自己的武力，置西園八校尉，即上軍、中軍、下軍、典軍、助軍左、助軍右、及左右八校尉，以宦官蹇碩為統帥。又因有皇帝的支持，原有的南北軍自然無法與之為敵。朝中大臣、想要鏟除宦官，甚至想仰賴地方軍隊，因此造成董卓之亂。

東漢時，除了京師軍隊北軍五營、虎賁、羽林之外，中央在地方設立常駐軍隊，號稱「營兵」。營兵主要受朝廷特別設立的都尉、校尉、謁者、將軍、中郎將等指揮，並和地方太守聯繫不大。其中主要有黎陽營、虎牙營、雍營、護羌校尉、護烏桓校尉、度遼將軍（度遼營）、匈奴中郎將、漁陽營、扶黎營、戊己校尉。

地方各郡郡兵則是平時只有千人，遇戰事臨時擴招，且受太守直接指揮。

屯邊的戍卒，多在邊防工事的亭障中服役。亭的防禦設備有用土做成的高墩，為四方或六角形，上有通信用的旗桿。士墩叫烽臺，又叫堠；四圍有牆叫塢，塢高約合市尺一丈鄉右，每邊長五丈餘。烽臺和塢合稱為燧。發現敵人時，則於烽臺上點燃烽火，敵人逼近，則據塢以守。兩亭之間，相距約十里。每隔三亭以上，有特備公務人員食宿的「傳舍」，設於亭的附近。備有傳舍的亭的，稱都亭。障較亭為大，亦有圍牆，可容二百人，也可以放烽火。亭多設於長城以外，障多設於長城沿線。障的首長為障尉；燧有燧長，由亭長兼任；均受太守、都尉的指揮。

漢代遇有徵伐，多自各郡國調兵出戰。戰時的統率系統，最高者為大將軍或將軍，皆臨時派定。將軍之下有部，大將可統五部，每部的首長為校尉（比二千石）和軍司馬。部下有曲，首長為軍候，曲下有屯，首長為屯長。至於地方的局部戰爭，則由郡都尉或縣尉、鄉官等統兵應戰。東漢後期的刺史，也可以統兵。

至於軍隊的調發，其權掌握在中央政府。國家有事，由中央下令調兵，太守發兵，西漢時由郡國都尉率領，東漢時郡國都尉裁撤，太守直接率領；至於中央下令時所頒的信物，高祖時用羽檄，是一塊長一央二寸的木偶，上插羽毛，表示疾速。文帝時，以虎符及竹使符調兵，虎符是銅製的虎形，竹使符是五寸長的竹片，上刻篆書。兩種符都是分成兩半，一半存於中央，一半存於郡國，中央欲調某一郡軍隊，則派使者持符前往徵調，太守勘驗屬實，然後指揮軍隊出發。但這辦法只限於內部，邊郡因應情形特殊，太守有自行發兵之權，漢代太守對軍事所負的責任很重，如有過失，會被彈劾為「乏軍興」，其罪重則死，輕則免。

募兵制

漢代的募兵，是東漢徵兵制破壞後才普遍施行的，但早在西漢武帝時，那時便已經兼用募兵。當時對外戰爭頻仍，徵兵不敷使用，因此必須於徵兵之外，再另外招募，八校尉的士卒，就是招募來的。此外，武帝也曾利用大量的刑徒及惡少年從軍。武帝以後，募兵事由更為常見，有時甚至招募異族為兵，例如宣帝時代的羌騎，就是招募羌人組成的騎兵。

東漢光武初年，鑑於多年水旱為災、連年戰爭造成戶口銳減，決定採取與民休息的政策，從建武六年至建武二十三年，共計五次罷省郡國兵。雖然百姓仍有隨時應召當兵的義務，但平時沒有受軍事訓練的機會，因此士兵素質大為降低。此外郡都尉也因節省軍費而停止執行訓練，各郡國的役政，乃陷於停頓狀態。但這種情形只限於內郡，邊郡則不廢都尉和都試。這種情況從光武帝之後，便一直持續下去，因此政府不得不募兵來臨時補充兵源。再來官部郡徵兵機構的撤銷，雖然東漢法律有徵兵的條文，但有事時臨時徵兵遠不如招募來得方便，因此徵兵的事，很少實行。靈帝時，黃巾亂起，屯兵不足以應付，因此大舉招募，皇甫嵩、朱儁等人的平亂軍隊中，便有大量的募兵。其後大將軍何進也會招兵買馬，以制宦官。

由於東漢政府提倡儒學，人民風從，藉由經術取得高官之位，對兵事自然感到厭棄。既然人民不願從軍，募兵的數量常感到不夠。而自光武帝以來，各種胡族，聚集於近塞或塞內，他們仍保持其原有的勇悍風俗，於是漢朝又招募胡人為兵。招募的胡人，大都用來守邊或用來攻伐不順的外族。光武時，匈奴南單于投降，光武移之於塞內，命其捍衛邊疆，兼拒北匈奴及鮮卑。東漢一代，除南匈奴外，尚有大批投降的鮮卑、烏桓、羌，為政府招募為兵。東漢採「以夷制夷」的政策，用這些歸降的胡人軍隊從事對外的戰爭。這種現象成為東漢滅亡的誘因之一。

募兵制的最大缺點，就是非常容易把國家的軍隊變成私人武力。因為募兵常為無家無業的人，沒有家庭和產業的牽掛，也沒有一定的服役期限；長官與他們長年生活在一起，只要善待之，他們自然會視長官如父兄，為之出生入死；這樣一來便會形成私人為中心的中心集團，於是軍閥就是這樣產生的。東漢時，羌人強盛，屢次侵犯西疆，中葉之後，成為東漢邊疆一個很大的威脅，政府見此情況之下，只好讓大軍長期防衛西邊各郡。這些軍隊因為經常與羌人作戰，戰鬥力很強，與內部缺乏軍事訓練的各郡比較起來，戰鬥能力自然相差很大。東漢末年，涼州爆發北宮伯玉之亂，隨後馬騰、韓遂等紛紛加入，漢靈帝多次派遣大軍都不能平叛。涼州也成為東漢末年率先脫離漢朝中央政府控制的地區之一。而出身涼州的董卓，控制了漢朝中央政府後導致各地郡守反抗，拉開了東漢末年軍閥混戰的大幕。

對外關係

匈奴

西元前3世紀，匈奴汗國被冒頓單于統治，武力十分強大，多次侵犯西漢邊境。前200年冬，劉邦親率大軍北上，匈奴軍隊佯裝後退，漢軍則迅速北進到平城白登山，卻在白登被冒頓單于的三十萬精銳騎兵包圍，劉邦與漢軍被包圍七天七夜，最後劉邦賄賂匈奴閼氏才得以逃出重圍。白登之圍後，西漢元氣大損，從此之後一直被迫與匈奴汗國和親。

為了抵禦匈奴的入侵，期間，西漢接續秦朝，繼續擴建延長長城，其西到起蒲昌海、東至鴨綠江以南、全長近一萬公里，是「中國歷史上最長的長城」。景帝在位時，西漢一方面繼續和親，同時也在邊境進行屯田移民，在國內則實行複馬令來增加馬匹，加強士卒訓練並大量製造兵器，這些都是預備反抗的準備。

漢武帝即位後，于元光二年（前133年）開始對匈戰爭。元朔二年（前127年），漢武帝派衛青以三萬鐵騎擊匈奴，收復河南地（新秦中）。元狩二年（前121年），又派霍去病出擊匈奴，出隴西，深入匈奴兩千餘里，奪得祁連山與河西走廊，切斷匈奴與西羌的聯絡，為西漢與西域之間開闢通道。元狩四年（前119年），匈奴入右北平郡和定襄郡，武帝派衛青和霍去病大舉回擊，至狼居胥山而還。從此，匈奴北徙漠北一直到公元前112年又南下。

但是，漢匈之間連年的戰爭嚴重損耗兩國的國力。武帝後期，漢改變國策，重新執行休養政策，而匈奴亦無力攻漢，僅能進行小規模騷擾。宣帝時期，匈奴虛閭權渠單于駕崩，隨後發生五單于爭立事件，分裂為五部；五單于爭立事件持續多年，剛平息後又是三單于爭立。其中一部首領呼韓邪單于通過臣服于漢的方式得到漢的支持，打敗各個競爭對手。但其三單于之一的郅支單于逃到西方，繼續與漢作對，元帝時期為漢校尉陳湯率軍擊斬。郅支單于被殺後，前已臣服于漢的呼韓邪單于深為驚恐，再次款塞，要求與漢和親。前33年，呼韓邪單于到長安，漢元帝以王昭君嫁與呼韓邪單于，號寧胡閼氏，是為昭君出塞，漢匈關係因此長期友好，邊境和睦，互市頻繁。其他的部分匈奴部落西遷到中亞康居一帶。

東漢前期，匈奴分為兩部，分別為南、北匈奴。其中南匈奴立呼韓邪之孫比為單于，對漢奉藩稱臣，漢在南匈奴設使匈奴中郎將，並把單于庭設于五原，以便支持和控制南匈奴。北匈奴立蒲奴為單于，在明帝在位時一度侵擾漢朝邊境，被擊退。章和元年，北匈奴為鮮卑所破，單于被殺，其中五十八部降漢。永元八年，車騎將軍竇憲等征伐北匈奴餘部，單于遁逃，竇憲在燕然山刻石紀功而還。此後，一些北匈奴南降東漢，另外一些則向西遷徙。而北匈奴故地逐漸為鮮卑侵占。

東漢後期，附屬于漢的南匈奴由于受鮮卑壓迫，屯居于五原、朔方、雲中、西河、美稷一帶，並逐步向內郡移徙。隨著時間的推移，使匈奴中郎將權力越來大，甚至擅行廢立匈奴單于。。獻帝時期，至曹操為丞相，分匈奴為五部，至此南匈奴不複存在。

三越

西漢立國之始，它的南邊有三個華夏部族和百越部族共同建立的國家，即東甌國、閩越國及南越國，統稱三越。東甌國據今浙江省南部，閩越國據今福建，南越國據今兩廣（即嶺南地區的廣東、廣西、海南和今越南）。這三國雖然受到漢高祖冊封，實際上為獨立，此種情況一直持續到漢景帝為止。到了漢武帝時，漢朝國力大為增強，三個國家的國力卻因為互相爭戰而相對衰弱，最後在漢武帝時期先後被滅，為了防止東甌及閩越再發生叛亂，於是將二國的人民遷徙至長江與淮水地區，另外將南越國之地分為南海、蒼梧、鬱林、合浦、珠崖、儋耳、交趾、九真及日南九郡，自此之後，這個地區再無大亂，光武帝建武十六年（40年），南越國地區發生叛亂，漢派馬援平亂，大破叛軍於浪泊，此後直到東漢滅亡，漢朝南疆未再發生動亂。

西羌

羌人分佈於今天青海省和甘肅省西南、四川省北部一帶。秦時羌人開始強盛，他們北與匈奴的河西地區為鄰，西北與西域相通。西漢初，匈奴冒頓單于勢力強大，西羌臣服於匈奴，中國與西域間的通道，完全被這兩個民族所隔絕。

羌在漢武帝時期被封閉在青海湖到西寧湟源縣湟中縣一線。「初開河西，列置四郡（河西四郡），通道玉門，隔絕羌胡，使南北不得交關。……羌乃去湟中，依西海、鹽池左右。」漢宣帝時代羌漢軍事對峙線在蘭州，「遂寇金城。」漢光武帝時代羌漢軍事對峙線在從西寧到蘭州一線來回拉鋸。

總地來說東漢初年羌漢軍事對峙線在今天京藏高速公路偏向西寧一帶拉鋸，期間羌漢雜居，時有衝突，臨羌縣是漢羌軍事對峙線最前沿。羌稱帝後，羌漢形勢發生巨變。羌人第一次攻入甘肅東南部。長安開始戒嚴，「置京兆虎牙都尉于長安，扶風讀為于雍。」也就是在這個時候，羌漢軍事對峙線發展到長安一帶，而一部分羌軍已經攻入山西上黨，而甘肅省西部已經不再屬于東漢。差不多在這個時候，甘肅戰場與寧夏打通，羌人和匈奴可以直接聯繫了。

其後任尚、鄧遵、馬賢時代，羌人稍弱，東漢稍微恢復了甘肅東部，「帝乃複三郡。使謁者郭璜督促徙者，各歸舊縣，繕城郭，置候驛。既而激河浚渠為屯田，省內郡費歲一億記。遂定安定、北地、上郡及隴西、金城常儲谷粟，令周數年。」「自羌叛十餘年間，兵連師老，不暫寧息。軍旅之費，轉運委輸，用二百四十餘億，府帑空竭。延及內郡，邊民死者不可勝數，並涼二州遂至虛耗。」東漢國家國力在漢羌戰爭中被大大損耗。「今三郡為未複，園陵單外。」充分說明了漢長陵等陵園直接暴露在羌人的進攻矛頭下。

在這種情況下，爆發了漢羌決戰。馬賢、趙衝之死標誌著羌軍對東漢全面戰略進攻的開始。

總結：由于西羌的內遷，和河西走廊、隴西當地的漢朝人時常發生衝突。最初，西北的地方官多數都殘酷苛暴，導致西羌反抗此起彼伏，西羌人屠殺漢朝人，西羌人在東漢取代了北匈奴成為漢朝第一外患，西北地區尤其是關中多次淪為戰場，羌人還曾一度兵進至山西河東。不但如此，剛崛起的鮮卑、南匈奴亦不時起兵南下，戰亂波及關中、陝北、陝南等地。此戰之後，使得關中更加荒蕪，成了羌、氐、匈奴、拓跋等族的混雜區，東漢西北人口大量內遷，導致河套以南地區也成了「羌胡區」。關中地區的經濟、人口一直等到北周時期才逐漸復甦。唯一倖免戰亂的西北地區是涼州西部，尤其是敦煌、酒泉和張掖等郡在戰爭時相對穩定，此地是後來張氏前涼的根據地。

東漢與西羌的戰爭嚴重損耗漢朝的國力，成為漢朝滅亡的誘因之一。董卓就是在東漢與羌的戰爭中崛起的漢軍將領。

西南夷

今雲南、貴州兩省，加上四川省的西部和南部以及甘肅省的南隅，這一片廣大的地區，在漢朝初期被許多異族所盤據，漢人統稱為「西南夷」，它們有的進入農業社會，有的則維持遊牧生活，並且建立許多國家。武帝時期，令唐蒙由筰關入夜郎，見其君多同，給予豐厚的賞賜，並告知其漢朝的聲威，說服其臣屬於漢朝，夜郎願意臣屬於漢朝。元光五年（前130年），漢於夜郎及其附近之地置犍為郡；並於夜郎置夜郎縣，以多同之子為令。同年，邛、筰、冉、駹等族，也希望得到漢朝的賞賜，請求成為漢朝的臣屬，於是漢在其地置十餘縣，由都尉統之，隸屬於蜀郡。但是過了幾年，西南夷屢次反叛，漢朝發動軍隊平亂，需要花費許多軍費。最後，武帝採納公孫弘的建議，放棄西南夷的經營，全力對付匈奴。已設的縣，大都廢棄。

元鼎五年（前112年），南越反叛，漢朝下令西南夷發兵幫忙徵討，西南夷不從。隔年，漢朝派郭昌、衛廣擊敗西南夷，在這些地方設立益州等郡。新設諸郡轄區中的各部族，皆因其舊俗而治理，不徵賦稅。地方政府的開支，則由內地各郡分攤供給。西南夷至此歸入漢朝疆域，西南夷內屬後，仍有小規模的叛亂，終西漢之世，未發生大型動亂。王莽時才開始大亂。東漢光武帝，敉平動亂後。到東漢時期，漢朝與這些地方聯繫更加緊密。

朝鮮

漢高祖時，衛滿朝鮮滅亡箕子朝鮮後，定都於王險，惠帝呂后時，為漢藩臣，雙方平安無事數十年。漢武帝時，衛滿的孫子右渠在位，對漢的態度轉為強勢，武帝派楊僕、荀彘率軍討伐，費時一年方能平定，漢在其地設置樂浪、玄菟、真番、臨屯四郡，其中以樂浪為最重要。昭帝始元五年（前82年），漢朝撤除臨屯、真番二郡，以其地合併到樂浪、玄菟。半島上的民族，非常複雜。半島北部，除了來自中國的朝鮮人外，尚有濊貉、沃沮等族。半島南部，尚有辰韓、馬韓、弁韓並立，通稱三韓。

在玄菟郡東北今松花江上游一帶，尚有一個夫餘國，高句驪人便是夫餘人的別支。元帝時，夫餘人朱蒙，率眾南下至朝鮮舊壤，建高句驪國，以高為氏，逐漸侵佔漢玄菟郡地。半島南部的「三韓」地區，也慢慢發生變化，宣帝五鳳元年，朝鮮遺族據辰韓地建國，號「徐羅伐」，後改稱「新羅」，新羅不久便奪取弁韓。到成帝鴻嘉三年（前18年），高句驪王族據馬韓地建國，號「百濟」。西漢末年朝鮮半島的形勢，大致是西北部是漢樂浪郡轄區，東北大部為高句驪所據；新羅據東南部地，百濟據西南部地。百濟、新羅因居半島南部，與漢朝沒有什麼關係，惟高句驪與漢接近，關係較密。它自建國後，對漢一直是稱臣的。後來東漢之後，高句驪時叛時降，成為漢帝國的東北大患。

倭國

漢朝時期，日本列島共有一百多個國家，皆是倭人建立的，漢人統稱為倭國。倭奴則是諸倭國中的大國，它座落倭國的極南界，當在今日本南部的九州島上。因倭奴的勢力較大，且距大陸較近，所以它首先代表諸倭國與中國交通。據說當時倭人飲食以手抓取食物，並有紋身、赤足、蹲踞的習慣；男子則盛行多妻，女子則不淫不妒。同時社會安定，極少盜竊爭訟的事。自漢武帝於朝鮮設四郡後，中國文化開始影響諸倭，諸倭通使於漢者達三十餘國，倭國也於此時開始對漢作歲時的貢獻，納貢的地點大概在樂浪郡。

光武初年，遼東太守祭肜威震北方，若干外族國家聞聲朝獻。建武中元二年（57年），當時正是日本史上的垂仁天皇時代，日本倭奴國王遣使來漢，漢賜一枚「漢倭奴國王」金印，曾於清乾隆四十九年（1784年）在九州北部發現，至今是日本的國寶。此時倭奴又於安帝永初元年（107年）和獻帝建安六年（201年）兩度來朝。到三國時代，雙方的交流更加密切。

烏桓與鮮卑

烏桓與鮮卑均屬東胡族。東胡位置在匈奴東邊，其活動範圍在內蒙古東部與遼寧省一帶。秦漢之際，東胡逐漸衰落，因此被匈奴雄主冒頓單于擊敗，餘部聚居烏桓山和鮮卑山，形成後來的烏桓族與鮮卑族。漢初，二族皆臣屬匈奴，武帝時，漢擊破匈奴左部，徙烏桓於上谷、漁陽、右北平遼東等郡，為漢朝監視匈奴的行動，並設護烏桓校尉管理，昭帝到西漢結束為止，烏桓雖然發動一些叛亂，不過沒有造成西漢太大威脅。

王莽篡漢後，因討伐匈奴，徵烏桓兵屯代郡，並以其妻子為質。烏桓因不服水土，相率逃亡，王莽因為這樣而殺害人質，烏桓決定投降匈奴。光武初年，烏桓與匈奴一同入侵漢朝，烏桓早已遷入中國塞內，造成中國北部居民，其生命與財產受到很大的侵害。建武二十年（44年），東漢派馬援征討烏桓，烏桓聞訊先行撤退。其後烏桓趁匈奴內亂之時進攻匈奴，把匈奴趕出大漠以南。東漢對烏桓的態度轉趨懷柔，允許烏桓人部分移居太原關內各地，駐牧於遼東屬國，再度為東漢監視匈奴，並複設護烏桓校尉管理，自此之後，烏桓為東漢保衛疆界。需要古代史料來源佐証

鮮卑居地與烏桓相接，言語風俗也與烏桓相同，但它在西漢時代，與中國沒有交通。東漢光武初年，匈奴又再度強大起來，命令鮮卑、烏桓一同劫掠中國北部。建武二十一年（45年），鮮卑與匈奴入侵遼東，為遼東太守祭肜打敗，鮮卑對東漢才感到畏懼。次年，匈奴南單于降漢，北單于孤立，鮮卑開始通使於東漢，東漢命令鮮卑攻擊北匈奴，鮮卑因此受到東漢許多賞賜。其後經明、章二代，鮮卑均恭順無事。不過到和帝初年，竇憲大破北匈奴後，鮮卑趁機佔據其地，此後漸漸強大，而成為東漢的邊患。

人口

秦末民變和楚漢戰爭，造成期間大量人口死亡。司馬遷在《史記》中感嘆：「初作難，發於陳涉；虐戾滅秦，自項氏；撥亂誅暴，平定海內，卒踐帝祚，成於漢家。五年之間，號令三嬗。自生民以來，未始有受命若斯之亟也。」漢五年（前202年）人口數在1500萬-1800萬人左右。此後由於奉行黃老政治、與民生息，到漢武帝時期的領土擴張，人口數量大幅提升。據《漢書·地理志》的記載，漢平帝元始二年（2年）有12,233,602戶，口數為59,594,978人。

由於中國歷史早期農業發展集中在黃河流域，故人口密度分佈為北多，南少。若以淮河、秦嶺為界，北部人口占據85%以上的比例，以南人口占據不到15%的比例。人口數超過500萬的司、豫、冀、兗、青、徐五州均位於黃河中下游地帶，這五州的人口總數占全國的55%。首都長安周圍人口密度達每平方公里1000人左右。人口數量在200萬以下的有交、涼、並、朔方四州。揚、荊、益三州的主要人口分佈在成都平原、南陽盆地、太湖平原和寧紹平原。

新莽末期，自然災害頻發，天鳳四年（17年）估計有5600萬人口，但是由于王莽改制失敗和天鳳元年（14年）的黃河改道導致隨之而來的綠林赤眉之亂和軍閥混戰，造成期間大量人口死亡。至建武中元二年（57年）時，全國人口數量僅2100.7820萬，僅相當于西漢元始二年的36.427%。後人口開始恢復增長。據《續漢書·郡國志五》所載，永和五年（140年），全國有戶969.8630萬，口4915.0220萬。至永壽二年（157年），全國有戶16,070,906，口50,066,856。東漢的人口分佈又有變化。新莽末東漢初期，大量的中原人民為躲避戰火向長江流域遷徙，南方人口升至全國四成。口數超過500萬的有豫、荊、揚、益四州。荊益兩州的人口都增加一倍，揚州人口也增加四分之一。南方人口增長的同時，北方大部分郡國人口減少。東漢晚期戰爭不斷，到晉武帝太康三年（282年），全國人口又只有1885萬人；只相當于125年前的三分之一。

經濟

農業

從西漢開始，鐵製農具已經開始成為主要的生產工具，著名的農具種類有鐵犁壁、矩犁、全鐵曲柄鋤等。牛耕是最主要的犁地方式，最重要的犁地法是二牛抬杠。一些新式耕田法，如代田法、區田法相繼誕生。國家注重興修水利，尤以關中地區為最。著名的水渠有成國渠、六輔渠、白渠等。在雒水附近有一條龍首渠，由于附近地區土質松軟易坍塌，就用鑿井的方法代替地上渠道，叫做井渠，極類似于今天新疆地區的坎兒井。東漢初期，出現翻車和渴烏等水利工具，增加農業生產效率。著名的農書有《氾勝之書》，裡面提到的相關技術，有效提昇農作物的產量。

手工業

西漢前期，冶鐵業分國營（中央政府）、官營（地方經營）和民營三種類型。當時著名冶鐵家有卓王孫、南陽孔氏等。漢武帝于元狩三年收冶鐵為國營，自此之後冶鐵業開始衰落，但由於此對國家財政較有利，之後一直沒有改變此政策。到了東漢光武帝在位時，冶鐵業改由社會自營，加上水排的發明，冶鐵業更加發達。銅器雖出現變少，但在兩漢時期仍是重要的金屬器。漆器則是兩漢時期重要的工藝品。漢朝的紡織業亦有國營與民營之分，民間著名紡織業者有陳寶光妻，她是織花機的發明者。到東漢前期時，蠶桑養殖在長江流域和嶺南等地開始推廣，特別是巴蜀地區。蜀錦更價值連城，在三國時代甚至成為蜀漢一大財源。麻葛製品中，最出名的是產于會稽地區的越布。

File:HanHorse.jpg|吉美國立亞洲藝術博物館館藏 漢代馬雕像

File:HK Museum of Art TST 加彩灰陶馬 Painted Grey Pottery Horse Han Dynasty.JPG|香港藝術館館藏 漢代《加彩灰陶馬》

File:Green glazed pottery dog Eastern Han 25CE 220CE.jpg|上海博物館館藏 東漢綠釉陶狗

File:Mawangdui silk banner from tomb no1.jpg|湖南省博物館館藏 馬王堆一號墓T型帛畫

File:Gansu Museum 2007 257.jpg|甘肅省博物館館藏 銅奔馬

商業及貿易

西漢初期奉行重農抑商政策，不過由於實施黃老政策，對於商人的影響不大。經過文景之治後，商業勢力大為篷勃發展，社會心理也隨之改變，當時俗諺流傳著「夫用貧求富、農不如工、工不如商」，「今法律賤商人，商人已富貴矣，尊農夫，農夫已貧賤矣」。雖然曾受到武帝「富國抑商」政策打擊，西漢後期，由於漢室政權中衰，商人勢力於是重新抬頭。到了東漢，政府並未制定限制商人獲利的法令，所以商業發展一向順利，但也造成貧富差距急劇擴大，加深經濟矛盾，東漢就在這樣的情況下導致衰亡。

兩漢的商業都會的分布，並沒有太大的改變，商業活動以黃河流域為主，淮河流域次之，長江流域又次之。當時各都會分布的區域，可以劃分為三大部：（一）關中區—以長安為中心都會，南控巴蜀，西北控天水隴西北地上郡等腹地。（二）關東黃河北岸—分為河東、河內及其相聯繫的燕趙區。河東區以楊、平陽為都會。河內區以溫、軹為都會。燕趙區以邯鄲與為都會。（三）關東黃河南岸—主要為河南區，並控馭齊魯梁宋三楚南越及穎川南陽區。河南區以雒陽為中心都會。

兩漢與西域的貿易最為盛行。。主要有兩條線南道與北道。南道以敦煌為起點，出玉門關至樓蘭，經大夏、安息、條支，過地中海至大秦，這條路線主要運送的貨物是絲織品，所以西方人稱為「絲路」。北道沿今天山南坡西行，越過蔥嶺北部，可抵奄蔡，並可通向大秦。這條路線主要運送的貨物是貂皮，因此被稱為「毛皮路」。

南越於武帝設郡後，南海的商業與交通開始蓬勃發展，當時這個地區中最大的商業都市是番禺，它是珠璣、玳瑁、果布的交易之處。其他如徐聞、龍編、也都是著名的商業城市。西漢時代的海上交通，可到達馬來半島的都元國與諶離國。東漢時，中國商船可到達錫蘭島的獅子國一帶，與印度也有直接交通。因此錫蘭島與南印度的佛教，也經由海上來到中國南部傳教，桓帝延熹九年（166年），羅馬帝國皇帝馬爾庫斯·奧列里烏斯，遣使由印度洋經日南徼外來漢，貢獻方物。

貨幣制度

西漢自建立以來，貨幣沿襲秦朝的半兩，但是品質低劣，實際重量往往只有八銖、四銖、甚至更輕，有的薄如榆聯，被稱為「榆莢錢」，貴族、豪商大肆盜鑄錢幣，造成幣制混亂。郡國鑄幣失控也是漢景帝時期七國之亂發生的原因之一。漢武帝即位後，一方面出于中央政府在經濟管理和政治統治上需要，另一方面由于對外征伐帶來的歲出增加令國庫日窘，故十分重視幣制問題，先後進行六次幣制改革。第六次改革推行「三官五銖」，一舉解決困擾西漢金融多年的私鑄、盜鑄問題，既穩定金融，又將漢高帝下放民間的鑄幣權重新統一于中央政府，於是幣製得到長期穩定。五銖錢成為自漢武帝時代直到隋朝七百餘年間國家鑄幣的主要形式。現在漢墓中經常出土的直徑約2.3公分，重量約3.5克的五銖錢，就是漢武帝時代第六次幣制改革產生的「三官五銖」。

西漢末期至新朝，王莽推行的一系列幣值改革一度引起幣制的混亂。到東漢初期，王莽幣才逐漸退出歷史舞台。

土地與賦稅制度

漢代的土地所有制與秦代相同，土地私有，並可自由買賣。土地所有者須向國家納耕地稅，耕地稅率為畝產的十五分之一或三十分之一。人口稅分為算賦和口賦。算賦是丁稅，十五至五十六歲的男女每年每人納一百二十錢（一算）。口賦是兒童稅，七至十四歲的兒童每年每人納廿錢。西漢早中期，政府積極推行「重農抑商」政策，壓抑富商豪強勢力，土地、農業問題曾一度穩定。到西漢後期，漢元帝廢除遷徙關東豪強前往關中漢帝陵區政策，土地集中日益嚴重，中央朝政腐敗黑暗，造成自耕農大量破產，淪為佃農。豪強莊園勢力日益強大。東漢早期，雖然重新推行重農政策，卻因富商豪強勢力已成，而無法撼動，造成地主莊園勢力的膨脹，其後東漢諸帝無力解決這個問題，加上人口不斷增加，而糧食生產又沒有跟上人口成長，終於爆發黃巾之亂，導致三國局面的形成。

宗教及信仰

漢朝為道教、佛教兩大宗教的形成及傳入期。

道教可以追溯到秦漢以前中國人固有的多神教信仰傳統、巫術信仰以及神仙說的崇拜。在這三者各自發揮的影響下，另外儒家學說又與黃老思想合流，加上災異、讖緯之說，濔漫兩漢社會，為道教信仰奠定群眾基礎，最後促使宗教性質的道教產生，是黃老思想和神仙家緊密結合的成果，自從漢武帝罷黜百家之後，黃老思想便開始消沉，此後便被神仙家方士運用，朝向宗教方面發展。方士們將其思想拿來與他們鼓吹的神仙方術互相結合，於是老子日趨神化，時間久了便成了道教的始祖。到了東漢，黃老已經成為宗教的名稱。叫做「黃老道」，不過此時還是道教的前身，直到張陵出世後，編纂經典，傳道收徒，建立固定的宗教儀式和宗教組織後，道教的雛形便宣告完成。東漢末年，道教分為兩大流派，一支為太平道；另外一支為天師道，亦稱為五斗米道。而五斗米道內部還有一個大支派，以于吉為教主，在長江下游地區傳播。

佛教在漢朝由印度經西域傳入中國。根據記載，漢哀帝元壽元年（前2年）博士弟子景盧出使大月氏，其王使人口授《浮屠經》。東漢永平十年（67年），漢明帝夢見金人，於是派人去西域，迎來迦葉摩騰與竺法蘭兩位高僧，並且帶來許多佛像和佛經，用白馬駝回首都雒陽，皇帝命人修建房屋供其居住，翻譯《四十二章經》。也就是現在的白馬寺。因此，在中國佛教史上，多以漢明帝永平十年作為佛教傳入之年。白馬寺成為中國第一座佛寺。《四十二章經》，也成為中國第一部漢譯佛經。馬伯樂認為這些記載純屬捏造，湯用彤則認為可能有部分屬實。147年安息人安世高到漢朝傳教譯經，167年月氏人支婁迦讖到漢朝傳教譯經。

巫覡活動，術數之學，這些民間禮俗迷信在漢朝社會相當普遍。比如傳統禁忌形式，曾經十分嚴格。湖北雲夢睡虎地秦簡《日書》中，就有關於行歸宜忌的規定。《日書》是選擇時日吉凶的術數書。在總計四百二十五支簡中，簡文直接涉及行歸宜忌的多達一百五十一支。漢武帝同樣「尤敬鬼神之祀」，曾經「作畫氣車，及各以勝日駕車闢惡鬼」。又在皇室活動中始用「越祠雞卜」之術。甚至在軍事行動中應用巫術，「丁夫人，雒陽虞初等以方祠詛匈奴、大宛」。民間禮俗迷信對正統社會機制有修補與維護的作用。中國古代「符瑞」迷信曾經成為政治文化的特殊內容之一。西漢時，漢文帝時見黃龍，漢武帝時獲白麟、寶鼎、赤雁，漢昭帝時鳳凰集、神爵集，漢成帝時甘露降，都被看作體現統治成功的「嘉瑞」。

文化

兩漢是中國曆史上科技與文化非常輝煌的一個時期。國家也非常重視教育和學識。文翁蜀郡作石室立學堂，為地方學校之始，爾後武帝令地方郡縣皆立學校，遂致「四海之內，學校如林，庠序盈門。」後漢國學猶盛，順帝以降，中央太學增至三萬餘生。漢人之學，皆重經驗、積往古之學說，因當時之風習，遂有發明製作之專家。

學術思想

漢朝初建，承襲秦法，當時的學術思想界，卻恢復春秋戰國時代，各家並立的狀態，因為秦朝滅亡後，學術思想的研究障礙已解除，雖然秦朝的「挾書律」及「妖言令」到惠帝、呂后時才廢除，但實際上未廢除前，政府對學術思想的研究，是不太過問的。戰國時代的儒、法、道、陰陽、縱橫五家，在漢朝初期依然活躍，但在中期以後，由於政府的提倡，學術界變成以研究經學為主。

漢代的治國思想。漢代在立國時用法家之法，又用道家黃老思想為主，文景時期，並輔以儒家和法家思想為法制指導思想，不僅強調無為，還注重禮與德的作用，既承認法律的重要性，又堅持約法省簡，務在安民。 而從漢武帝之後，統治者又確立儒家思想成為正統思想，並輔之以法家思想為法制指導思想，其中心是「德主刑輔」，即先用德禮教化，教化無效再施之以刑罰。這種剛柔相濟的治國之道，成為漢武帝以後漢王朝法制的指導思想。這一思想對後世歷代王朝的立法影響很大。漢宣帝曾有名言：「漢家自有制度，本以霸王道雜之。」便是這種思想的精闢闡述。

早在秦始皇焚書坑儒所毀壞的很多文獻，通過漢代學者的記錄得以重現，包括五經當中的古文尚書，也是這時候發掘整理出來的。漢初的經書，全由私人傳授，漢武帝採納董仲舒的意見「罷黜百家，獨尊儒術」後，經學成為學術主流，經學家也愈分愈多。由于不同學者對經書的理解與記憶有所不同，經學也被分為不同流派。宣帝時期，在太學中立學官的，《易》有三家，《書》有三家，《詩》有三家，《禮》有一家，《春秋》有兩家，共十二博士。東漢初年，增加到十四博士。學者都尊崇其師以及學說，世代不替，因此學派的區分，日益嚴格。

兩漢的儒家，雖然尊崇孔子，不過也受到陰陽學家的影響，因此他們的學說，開始出現宗教的迷信色彩。例如京房易專重卜筮，大小夏侯尚書喜論五行之說。武帝時，董仲舒治公羊，著春秋繁露一書，其中也有不少離奇的話，此外他也提出「天人感應」，敦促君主施行仁政。成帝時的劉向，治穀梁，也多次以禍福附會其說。總之，這些學者認為天降的祥瑞或災禍，全是受到人事的影響，尤其是君王的賢愚勤怠，有非常密切的關係，由於武帝以來，君王的權力已經大為提高，唯一還有所顧忌的便是天災異變，當時學者常使用這種論調來批評當時朝政。

西漢末年，儒學附會陰陽學說後，天象人事的比附，演變為「讖緯之學」的出現，內容更為奇特。讖緯大都出於當時人之手，而偽託為古人的著作。這種神話思想的風行，使得儒學的人文精神和實踐精神遭到敗壞，也造成王莽篡位的理論基礎，光武帝同樣因為圖讖，最終建立東漢王朝，統一天下後，由於他特別篤信讖緯，在處理政務遇到紛爭，猶疑不定時，常常借重讖緯來幫助決策。又在建武中元元年（56年），又曾經正式「宣布圖讖於天下」，進一步確定圖讖作為法定經的地位。讖緯神學的尊嚴得到政治權力的庇護。造成當時「儒者爭學圖緯，兼復附以妖言」。因此讖緯的地位，在某種意義上甚至超過經書。後來曹魏代漢，也造作讖言「代赤者，魏公子」，「鬼在山，禾女連，王天下」。利用民間讖緯迷信，以實現政權的更替。

西漢晚期，劉歆發起研討古本經籍的運動，他根據漢代陸續發現的古文經書，如春秋左氏傳、古文尚書、逸禮等，另立解說，此外他也將毛詩也列為古文，與今文家相抗衡，引起「今古文之爭」，他不但提倡研究古文經書，更主張設置上述四經博士，不過為當時今文家所反對，立學官的事，終告失敗。不過民間研究古文之風大盛，學者輩，明帝時的賈逵，桓帝時的馬融，都以治古文名家，到東漢晚期，古文經學走向發達，今文經學日益衰微。古文學最大的貢獻，是把經學從今文家的荒誕迷信的經說，引導考據訓詁之途。

文學與史學

賦是漢朝流行的主要文學體裁，由《楚辭》發展而來，賈誼是為賦的開創者，他的作品《弔屈原賦》、《鵬鳥賦》等作，借物抒懷，意境深沉，同時在抒發情感之外，兼言哲理，這是文學由通俗體走向文人體的表現。賈誼的賦作氣力雄勁，但文採不艷，在他之後的賦家，則完全著重於辭藻的鋪陳，作品更趨文人化。武帝時代的枚乘、枚臯、東方朔，更趨向於這個方向，到司馬相如的《子虛賦》、《上林賦》，這些賦作氣勢恢宏，代表時代精神的豪邁勇進、物質生活和精神生活的豐富多彩。西漢後期，最有名的賦作家是揚雄。東漢時期，則以班固、張衡的作品地位最高。東漢後期，長篇賦逐漸變少，各種抒情寫物的短篇賦開始流行，與先前的長篇賦文辭藻華麗的風格逐漸漸行漸遠，意境較為清新。

漢武帝時設立樂府，搜集民間詩歌，並令詞臣製作詩歌，協以音律，即為樂府詩，樂府的句府雖然參差，但以五言最為突出，它促進五言詩的產生。樂府歌辭本來配題、配樂，各有其特定用途，其後，襲舊題舊樂而改歌辭；或僅借舊題，樂辭均改；乃至題、樂、辭均改之例日益孳多，辭與樂的關係乃漸漸疏離，最後完全無關，成為徒詩—僅供閱讀的作品。其特色是詩人以極昏混亂的景、極沉重的口吻描寫戰爭之頻繁、慘烈、以及陣亡者的忠勇與悲哀，完全呈現現實世界的不堪，給人極為強烈的震撼。樂府詩為中國古典詩注入寫實的精神，建構寫實傳統堅實的基礎。代表作品為《陌上桑》與《孔雀東南飛》。

古詩與樂府詩同起源於漢代，主流形式是五言，五言之外，也有七言的形式。大抵由樂府詩演變而成。兩漢時代處於發展階段，到東漢末年才趨於極盛。其特色為：章法上，句數不定，可自由伸縮，不受限制，但通常為雙數句；韻法上，以連句韻及隔句韻為常見，可自由換韻，用韻較寬。代表作品為：東漢班固的《詠史詩》，象徵五言詩的正式成立、《古詩十九首》，樸實自然，感傷抒情，為五言詩最早成熟的作品，後來在魏晉南北朝更為篷勃發展，曹魏曹丕的《燕歌行》，象徵七言詩的正式成立，南朝宋鮑照以後才逐漸發展。

漢代的散文，繼承先秦諸子系統的論說理文，作品特色是大段鋪排，氣勢雄渾。句式厚重樸實又不失變化，最具代表作者仍是賈誼。他的《治安策》，對文帝、景帝、武帝三朝政治情況的發展有著深厚的影響，僅以文章而論，其辭理的暢達，剖析的深刻，以及氣勢的高昂，為散文開創獨樹一格的境界。他的另一本著作《過秦論》，體裁與賦接近，這篇論成為魏晉六朝人著論的典範。其他有名的書策作者有晁錯、董仲舒、司馬遷等。晁、董的作品，皆流暢適切；司馬遷的文章，與當時辭藻華麗的風格與眾不同，以「辨而不華，質而不俚」的手法建立自家的風格，他的最具代表作品為《報任少卿書》，字句間充滿情感，也是漢代的散文名作之一。

在史學方面，漢朝史官司馬談之子司馬遷的《史記》是中國歷史上第一部紀傳體通史，也是二十四史中的第一部，為以後兩千年正史的編纂提供規範。全書分為十二本紀、十表、八書、卅世家、七十列傳，共一百卅篇，五十二萬六千五百字。班固所編寫的《漢書》分為十二紀、八表、十志、七十列傳。全書體例仿效《史記》，惟改「書」為「表」，廢「世家」入「列傳」，還開創刑法、五行、地理、天文、藝文四志和《百官公卿表》。《漢書》是中國曆史上第一部內容完整的斷代史。更是成為以後歷代王朝撰寫本朝歷史的範本。而兩漢時期其他的史書還有《東觀漢記》、《漢紀》和《吳越春秋》等。很多西方學者認為，漢代的作家所開創的史學標準，直到18世紀都一直領先于世界。

書法

漢代的主要書寫文字為隸書，從秦代隸書發展而來。「隸書」又稱「佐書」、「古隸」、「今隸」、「八分書」。隸書具有以下特色：一、隸書的最大特點是由直線構成，它不像小篆由相互連接的圓轉，有時又有逆向書寫的線條組成，而是由散開而平直方折的筆畫構成，凡逆筆都變為順筆，書寫起來不僅順手，而且快速。二、筆畫難以呈現具體的形象，古文字象形的特質從此消失，而且形體多已不合六書原則。三、漢字發展至隸書已經徹底「符號化」。隸書對大、小篆加以省略、簡化，結構單純許多，就是做為日常生活書寫工頁，不啻為一大進步。另外篆隸形成中國書法藝術主流，漢代時期，隸書漸漸取代小篆成為主要書寫字體，隸書的出現奠定現代漢字字形結構的基礎，成為古今文字的分水嶺書法。隸書經過兩漢的發展後，又發展出另一種字體「楷書」，最後成熟於唐代。

藝術及工藝品

漢代的藝術活動，繼承和發揚先秦多種形式藝術與技術的基礎，造形意識從萌芽逐漸趨於成熟；西域與佛教外來藝術的傳入，更豐富漢代繪畫與雕刻的題材與技法，表現出極高的原創性。無論陶兵馬俑、歌舞俑還是畫像石、畫像磚，工匠懂得雕刻這些作品的人、神、獸。工匠除了用特殊的藝術手法塑造和描畫古代著名人物、神仙妖魔和珍禽異獸，也能以寫實的手法描繪當時生活中的達官貴人、文臣武將乃至工匠農夫。

漢代陶俑的最高水平表現在歌舞俑上。西安出土的舞女俑，扭動腰肢，揮舞雙臂，挪動舞步，正在輕歌曼舞。舞女身穿舞裙，纖細的腰上束著寬腰帶，兩條寬大的舞袖隨風擺動，像長而輕的紅綢。這座塑像體態輕盈，動作優美富于動感；舞衣和長袖柔軟而飄，顯得非常生動。從歌舞俑的造型來看，漢代工匠已經確實掌握人像塑造的技巧，尤其是人物在運動時，肩、胸、腰、腿的變化關係，給人像注滿活躍的生機。漢代最具代表性的石雕為霍去病陵墓石雕。內部有馬踏匈奴、臥馬、躍馬、臥虎、臥象、臥牛、石蛙、石魚、野人、野豬、石蟾、母牛與小牛，人與熊等造型。。麻浩崖墓的石雕佛像是中國最早的佛教造像之一。由於近代以來，漢代青銅器大量出土。這些青銅器有兩個特點：一、青銅器出土的地域非常廣大，除了文化發達的黃河和長江中下游地區外，偏遠的雲南、貴州、廣東等地，也發現精美的青銅器。二、青銅器的種類比較齊全，既有皇親國戚墓葬裡的豪華器具，也有一般墓葬裡的各式生活用品，還有雲南、貴州等地各民族的具有充滿地方特色的青銅器。

繪畫品類多為帛畫、壁畫、畫像石、畫像磚。

漢朝帛畫作品極多，然而至今已幾乎無存，唐朝張彥遠的《歷代名畫記》就指出漢朝帛畫數量繁多，然而經天災人禍後毀壞極為嚴重。現在能見到的漢代帛畫作品是出自漢墓的「非衣」、「銘旌」（旌幡）等隨葬品。這是時下所見最早的記錄現實生活的大型繪畫作品。惜剝損較重，只能觀其大略。最完整的為馬王堆漢墓出土的帛畫，描繪墓主人的地上和地下生活。而長沙楚墓出土的帛畫《龍鳳仕女圖》，是中國最早繪畫作品之一。西漢壁畫的幻想氣氛相當濃厚，從已發現的雒陽墓室壁畫來看，題材多集中於青龍、白虎、朱維等方位神，荷花，靈芝等仙草，還有日月星象、後龍升天、乘風成仙等神話內容，其風格與戰國帛畫有承襲關係。東漢墓室壁畫雖然以仍然以升天、避邪、鬿福為主要內容，但是加強繪畫的人文因素，表現生活的場景明顯增多。畫像石在漢代陵墓地面建築的石闕、石亭祠的壁面上，地下建築墓室的石構件上，往往雕刻出各種人物故事、生活過程和動植物形象，人們一向稱之為「畫像石」。漢代畫像磚的數量上雖然沒有比畫像石多，但仍有其歷史意義與藝術價值。漢代畫像磚是由戰國和秦代的瓦當、空心磚上的畫像演變而來的。

表演藝術

西漢初年，先秦雅樂已多數失傳，但民間音樂在上層社會上中頗為盛行。他們尤其喜愛楚歌。，楚漢戰爭末期，西楚霸王陷入「四面楚歌」的困境，對著虞姬唱出《垓下歌》：「力拔山兮氣蓋世，時不利兮騅不逝，騅不逝兮可奈何」。張騫通西域後，把西域的摩訶兜勒曲和蒙古的北狄樂帶回中國，當時樂官李延年據以製成「新聲二十八解」，聽到的人都大受感動。從此，中國的音樂在民間音樂和外族音樂的互相交融下更加蓬勃發展。從這個時侯開始，中國音樂有古樂和胡樂之分。古樂是指上古以來的傳統的本土音樂，胡樂則指從外族胡人吸收的音樂。另外漢武帝時設樂府，採集許多民間歌謠與外來歌曲後，在東漢末年，出現琴曲《垓下歌》，表現出中國古代音樂的陽剛之美。

漢代舞蹈是以楚舞與中原舞蹈、中原與西域舞蹈的結合為特色。它改變先秦以來縱向承襲為主的格局，開闢縱橫吸收、交流、結合發展的新局面。由於西域和西南越等少數民族樂舞、雜技、幻術的傳入，表演性質舞蹈技藝的大幅提高，著名舞蹈作品和舞人的出現，樂府對民間樂舞的廣泛採集，舞蹈表演活動普遍興盛起來，出現中國歷史上第一個舞蹈藝術發展的高潮。

中國戲劇在漢代處於發展階段，漢代民間的各種演出總稱為「百戲」，包括歌舞、雜技、武術等各類伎藝形式。秦二世就有「角牴」戲，到了漢朝蔚為風行。張衡《西京賦》描繪，就有角牴戲，提到「東海黃公」，「戲」裡一個演員扮黃公，以紅綢束髮，佩赤金刀；一個演員扮成猛虎。博鬥的結果，黃公被虎咬死。表演為代表體，顯示出簡單的戲劇性，可以視為中國戲劇的胚胎。

建築

漢代在中國古代建築史上，是承先起後的時代。漢代建築有以下特色：一、布局和結構均勻、對稱。二、門窗變化自由，有多種樣式出現。三、頂部舒展而優美，基部氣派而穩固。四、常分利用其他造型藝術，使繪畫、雕塑等各方面藝術裝飾於建築。五、木料的框架總是顯露出，建築物的基本輪廓。六、城市規畫嚴謹方整。七、園林布置靈巧別緻。

漢代聞名於世的建築，如：兩都長安、雒陽和成都的建設，大量宮室、離宮、苑囿的興建，長城防禦體系的延伸與修繕，大規模營造陵墓、壇廟等等。其面積廣大、數量亦多，達到前世前所未有的地步，形成中國建築發展史上的高峰。漢代生產技術的發展和鐵工具的大量使用，對建築上的材料與應用，甚有幫助。

科技

數學

公元前一世紀的《周髀算經》及東漢初年的《九章算術》則是數學領域的傑作。其中，《九章算術》是戰國、秦、漢古代社會創立並鞏固時期數學發展的總結，列有分數四則運算、今有術（西方稱三率法）、開平方與開立方（包括二次方程數值解法）、盈不足術（西方稱雙設法）、各種面積和體積公式、線性方程組解法、正負數運算的加減法則、勾股形解法（特別是勾股定理和求勾股數的方法）等籌算方法，形成一個以籌算為中心、與古希臘數學完全不同的獨立體系。1983年至1984年，《算數書》在湖北江陵張家山漢墓中出土，《算數書》的發現，對《九章算術》的完成，有著直接的影響，也改寫中國古代數學史，將中國古代數學的歷史推前三百年。

天文學

在科技方面，東漢張衡製成世界上第一台能夠感知地震的地動儀，另外撰有《靈憲》一書，解釋天體演運。前104年，司馬遷、唐都、落下閎等人制定的《太初曆》第一次將二十四節氣訂入曆法。85年，又改用《四分歷》。

醫學

兩漢出現許多名醫。西漢的淳于意、東漢的張仲景、華佗等等。西漢淳于意，留下25例病歷紀錄，對治癒和不治都有客觀的分析，在中國古代醫學史上，具有創始的意義。張仲景因《傷寒雜病論》而被尊為「醫聖」。而史書記載華佗更是世界上最早採用全身麻醉的醫師（華佗是否真有其人仍受到史學家陳寅恪等人的質疑）。俞跗運用人體解剖術治病。

《神農本草經》是這一時期著名的藥典，共收錄藥物365種，分上、中、下三品，上品敘述滋補藥物，中品敘述滋補和治病兩種性能的藥物，下品是專門治病的藥物，這為中國後世的藥物分類法提供一定的參考。針灸也得到突破性發展，東漢前期的《黃帝明堂經》，初步建構傳統的腧穴學，用來服務於針灸臨床。與《黃帝明堂經》同時問世的《難經》，提出「命名」的新說，進一步確立陰陽五行學說對傳統醫學理論的指導地位。

農學

漢代出現不少農學著作，其中以《氾勝之書》與《四民月令》最為著名。

《氾勝之書》是中國歷史上第一部完整的農學著作。該書講及當時的耕作的基本原則、播種日期、種子處理、個別作物的栽培、收穫、留種和貯藏技術、區種法等。氾氏的農學成就在漢代產生深遠的影響。東漢末年鄭玄注《周禮》和《禮記》，都曾經引用「氾勝之術」和《氾勝之書》。唐朝人賈公彥《周禮疏》：「漢時農書有數家，《氾勝》為上。」，成書於二世紀中期，敘述田莊從正月直到十二月中的農業活動，對古時穀類、瓜菜的種植時令和栽種方法有所詳述，亦有篇章介紹當時的紡績、織染和釀造、製藥等手工業。

工藝技術

漢代也是中國最早發明瓷器燒造的時代。這個時期還發明蒸餾法、水力磨坊、現代馬軛和肚帶的原型、漆器、用于冶金的往復式活塞風箱、出現于漢末的獨輪車、水車和吊橋。造船已經採用船尾柱舵。兩漢時期，中國的冶煉技術也有長足的發展和進步，鑄錢技術成熟，如三銖錢、五銖錢等。彩繪工藝獨特，如馬王堆所出土的帛書彩繪，各種生活用品齊全，如有「漢代魔鏡」之稱的銅鏡，煮鹽技術也不斷提高，兩漢出現蒸餾酒，釀酒水平臻于完美。農業技術大幅度提高，東漢早期出現水排等新式灌溉工具。

紙的發明與傳播

西漢中後期，宮廷內已出現一種絲質的紙，叫做赫蹏。在東漢，漢和帝時（105年），宮內宦官蔡倫改進造紙術，大大降低造紙成本，取代簡帛成為主要的書寫材料。造紙術在西元3世紀後傳入朝鮮半島和日本，在751年發生的怛羅斯之戰後又傳入中亞，之後通過阿拉伯諸國進入北非與歐洲，改變世界文明史。

交通

漢朝社會頻繁的移動行為，成為商業發展有利的條件，加速物資的流通速度，「農商交易，以利本末」，因而使得經濟生活表現出前所未有的活力。當時「重裝富賈，周流天下，道無不通」，「千里游赦，冠蓋相望，乘堅策肥」，「船車賈販，周於四方」，「東西南北，各智巧」。以繁忙的移動行為為基礎的民間自由貿易，衝破政府抑商政策的多重限制，對於秦漢經濟的繁榮表現出顯著的歷史作用。

另一方面，交通建設的發達，對於漢朝政權統一也有所助益，有的學者曾經指出：「交通的便利，行旅安全的保障，商運的暢通，驛傳制度的方便，這些因素都使漢代的人民得以免除自身的地域中心之見，他們的所見所聞比較全面且充實，知識容易傳播。漢代上層階級大多走過許多地方，因此對於「天下」全貌了解得較為清楚，也加強他們對於統一的信心。這一點不僅影響到當時人政治生活心理的健康，而且能鞏固全國文化的統一性。

交通建設技術性的進步，除了表現在道路和運河的建設外，車輛和舟船的普及和運輸動力的改良，也具有重要的意義。在這一段時間。「鹿車」製作簡易，偶爾也可以用來運貨和載人，戰國時期發明的雙轅車，漢代民間社會也開始普遍使用。由於畜牧業的發展，馬、牛、駱駝等牲畜，廣泛作為車輛動力的牽引來源，這些物品與動物的應用，為當時的生活帶來不少的方便。

社會

兩漢均是初期經歷戰爭，天下殘破，經濟凋敝，初期的皇帝往往會自奉節約，以身作則，社會風氣較為儉僕，不過隨著時間的推移，當政治安定、經濟發展、社會富裕後，這時的皇帝沒有繼續維持節儉風氣，甚至起來帶頭放縱享樂，於是奢侈之風便會由上而下蔓延，社會風氣自然會轉向浮華與奢靡，而造成嚴重的社會危機，而導致王朝的解體。

漢代社會根據政治、經濟、法律地位及享受特權的多寡，社會民戶可以劃分為「貴」、「良」、「賤」三個等級。「貴」包括皇帝及其宗室、外戚、軍功後裔等。這個等級高居社會上層，掌握統治權力，享受很大特權。「良」包括豪族地主、商人地主、廣大的自耕農和半自耕農。這個等級具有自由身份，雖然財產貧富懸殊很大，不過一樣處在被統治地位，沒有享受到多少特權。「賤」包括豪強底下依附民、賓客、奴婢等，這個等級的最大特點是人身自由受到限制，處在被國家或豪強大族嚴格管理和控制的地位。

漢代的社會生活方面，貴族人士穿著長袖的袍服，並穿戴頭巾，平時收取田租為主，他們得以養尊處優，進行其他的娛樂活動，儒學成為中國文化的主流後，讓其子弟研習經學，將勢力擴散至政治地位上，於是土地兼併現象便難以阻止且日益嚴重，一般平民則穿著睡衣寬鬆褐和續鼻褲，偶爾還加一件及膝之短袍。一般以小家庭為最基本的經濟組織，但種田時需要鄰里的合作。主要的農作物為米及稷黍。婦女以蠶桑為常業，由於大部分收入要繳交給地主，因此僅能勉強維持生活，當政府給予傜役過重或遇到天災人禍，這時農民不是依附豪強為奴，就是鋌而走險發起革命。

漢代延續秦代，以皇帝為核心，以郡縣制為基礎的專制主義中的中央集權制正式成為主要的政治制度；地主經濟取代領主制在統一國家範圍內得以確其主導地位；「書同文，行同論」、「罷黜百家，獨尊儒術」的文化思想統一等，這些都成為中國兩千年封建社會開創先河。在社會結構上，皇帝、皇室貴族及異姓貴族、官僚士人、平民、奴婢賤民之類的等級集團，大體形成。漢代土地兼併、農民起義及社會周期性動蕩等社會現象，都在後代各王朝不斷重演。

西漢立國，以軍事功臣作為統治集團的核心，戰爭中「攻城先登」與「趣功戰疾」者得以立功封候。戰爭的特殊背景對社會生活心態產生深刻的影響，所謂「剽輕」、「剽疾」的節奏風格，一時在當代文化心理比較中居於顯著的優勢。接著在文景時代視社會背景，實行寬仁之政，政府對秦時苛急之政深切反省，以「無為」原則加以改變。但是「無為」並不代表消極怠惰。其實漢文帝和漢景帝二人本身是相當勤政的。那時政府鼓勵「勤身從事」，文景之世所謂「天下翕然，大安殷富」。漢武帝親政後，以武力征討四方，開疆拓土，尚武之風大起，影響到社會節奏而轉為緊湊。一時「有氣敢狂」之士多以「用善騎射」而得功名。戰爭背景所啟動的勇進精神對社會風氣的影響，可以說一直持續到西漢結束為止，雖外西漢有「輕俠」之稱。西漢官吏尹賞曾以嚴厲手段打擊威脅治安的「長安中輕薄少年惡子」。西漢「少年」好勇鬥狠，激進豪放的性格特徵，代表時代精神的某種傾向。

東漢立國，社會風氣有所轉變。社會生活節奏趨於舒緩，由於光武帝、明帝、章帝三朝推崇儒學，民間學子爭相學習儒學，儒學正統對民間所謂「輕」的風習，一向持否定的態度。儒者講究安詳凝重，而鄙視輕狂疏放，另外馬援侄子馬嚴、馬敦「通輕俠客」。馬援曾在交趾前線寫信提醒他們，不要仿效俠者的行為，此舉不會得到社會的尊重，以致「陷為天下輕薄子，所謂畫虎不成反類犬」。也以「輕薄」指違背儒學生活的行為傾向。以「輕」為特徵的生活節奏當時受到社會的非議。而東漢時期北邊軍事形勢已經發生重大的變化，「匈奴既分，羽書怖聞」，南疆蠻夷也「往化既孚，改襟輸寶」，在外患壓力減輕之下，光武帝中期後以後，國家無戰爭，於是東漢長期以來是輕武備而重文治，而「專事經學」，社會上瀰漫著淳美的政教之風，並且士人也開始輕視武人。

漢代的婦女地位，遠比後世多數朝代來的高。呂后曾把持朝政十五年，東漢時期，臨朝太后多達六位，「多女主臨朝，不得不用其父兄子弟，以寄腹心，於是權勢太盛。」，造成外戚勢力一再抬頭的原因。漢代貴族婦女在婚姻關係和家庭生活中佔據較高地位，也留下深刻的歷史烙印。「使男事女，夫詘於婦」的情形在民間也有表現。婦女有較高的社會地位，在有些地區甚至長期成為一種民俗特徵。漢代寡婦不受約束，西漢丞相陳平的妻子，嫁給陳平之前曾五次守寡。在婚姻離異時也可以採取主動，同樣是漢代婦女的權利。但在劉向、班固、班昭等人提倡從一而終情況下東漢時期恪守貞節的女性人數較西漢時期有了大幅的增加，越來越多的婦女開始自動守節。漢代文化融合多種文化因素初步形成的時代，儒學禮制尚未能規範所有的社會層面，「夫為妻綱」的性別統治局面也尚未成型，於是存在「婦人尊貴」的現象。

君主年表

相關條目

• 阿巴坎遺址

• 燕然勒石

注釋

Etymology

According to the Records of the Grand Historian, after the collapse of the Qin dynasty the hegemon Xiang Yu appointed Liu Bang as prince of the small fief of Hanzhong, named after its location on the Han River (in modern southwest Shaanxi). Following Liu Bang's victory in the Chu–Han Contention, the resulting Han dynasty was named after the Hanzhong fief.

History

Western Han

China's first imperial dynasty was the Qin dynasty (221–207 BC). The Qin united the Chinese Warring States by conquest, but their regime became unstable after the death of the first emperor Qin Shi Huang. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xiang Yu (d. 202 BC) of Chu and Liu Bang (d. 195 BC) of Han, engaged in a war to decide who would become hegemon of China, which had fissured into 18 kingdoms, each claiming allegiance to either Xiang Yu or Liu Bang. Although Xiang Yu proved to be an effective commander, Liu Bang defeated him at the Battle of Gaixia (202 BC), in modern-day Anhui. Liu Bang assumed the title "emperor" (huangdi) at the urging of his followers and is known posthumously as Emperor Gaozu ( BC). Chang'an (known today as Xi'an) was chosen as the new capital of the reunified empire under Han.

At the beginning of the Western Han (西漢 Xīhàn), also known as the Former Han (前漢 Qiánhàn) dynasty, thirteen centrally controlled commanderies—including the capital region—existed in the western third of the empire, while the eastern two-thirds were divided into ten semi-autonomous kingdoms. To placate his prominent commanders from the war with Chu, Emperor Gaozu enfeoffed some of them as kings.

By 196 BC, the Han court had replaced all but one of these kings (the exception being in Changsha) with royal Liu family members, since the loyalty of non-relatives to the throne was questioned. After several insurrections by Han kings—the largest being the Rebellion of the Seven States in 154 BC—the imperial court enacted a series of reforms beginning in 145 BC limiting the size and power of these kingdoms and dividing their former territories into new centrally controlled commanderies. Kings were no longer able to appoint their own staff; this duty was assumed by the imperial court. Kings became nominal heads of their fiefs and collected a portion of tax revenues as their personal incomes. The kingdoms were never entirely abolished and existed throughout the remainder of Western and Eastern Han.

To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu ( BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was troubled about the abundant Han-manufactured iron weapons traded to the Xiongnu along the northern borders, and he established a trade embargo against the group.

In retaliation, the Xiongnu invaded what is now Shanxi province, where they defeated the Han forces at Baideng in 200 BC. After negotiations, the heqin agreement in 198 BC nominally held the leaders of the Xiongnu and the Han as equal partners in a royal marriage alliance, but the Han were forced to send large amounts of tribute items such as silk clothes, food, and wine to the Xiongnu.

Despite the tribute and a negotiation between Laoshang Chanyu ( BC) and Emperor Wen ( BC) to reopen border markets, many of the Chanyu's Xiongnu subordinates chose not to obey the treaty and periodically raided Han territories south of the Great Wall for additional goods. In a court conference assembled by Emperor Wu ( BC) in 135 BC, the majority consensus of the ministers was to retain the heqin agreement. Emperor Wu accepted this, despite continuing Xiongnu raids.

However, a court conference the following year convinced the majority that a limited engagement at Mayi involving the assassination of the Chanyu would throw the Xiongnu realm into chaos and benefit the Han. When this plot failed in 133 BC, Emperor Wu launched a series of massive military invasions into Xiongnu territory. The assault culminated in 119 BC at the Battle of Mobei, when Han commanders Huo Qubing (d. 117 BC) and Wei Qing (d. 106 BC) forced the Xiongnu court to flee north of the Gobi Desert, and Han forces reached as far north as Lake Baikal.

After Wu's reign, Han forces continued to fight the Xiongnu. The Xiongnu leader Huhanye Chanyu ( BC) finally submitted to the Han as a tributary vassal in 51 BC. Huhanye's rival claimant to the throne, Zhizhi Chanyu ( BC), was killed by Han forces under Chen Tang and Gan Yanshou (甘延壽) at the Battle of Zhizhi, in modern Taraz, Kazakhstan.

In 121 BC, Han forces expelled the Xiongnu from a vast territory spanning the Hexi Corridor to Lop Nur. They repelled a joint Xiongnu-Qiang invasion of this northwestern territory in 111 BC. In that same year, the Han court established four new frontier commanderies in this region to consolidate their control: Jiuquan, Zhangyi, Dunhuang, and Wuwei. The majority of people on the frontier were soldiers. On occasion, the court forcibly moved peasant farmers to new frontier settlements, along with government-owned slaves and convicts who performed hard labor. The court also encouraged commoners, such as farmers, merchants, landowners, and hired laborers, to voluntarily migrate to the frontier.

Even before Han's expansion into Central Asia, diplomat Zhang Qian's travels from 139 to 125 BC had established Chinese contacts with many surrounding civilizations. Zhang encountered Dayuan (Fergana), Kangju (Sogdiana), and Daxia (Bactria, formerly the Greco-Bactrian Kingdom); he also gathered information on Shendu (Indus River valley of North India) and Anxi (the Parthian Empire). All of these countries eventually received Han embassies. These connections marked the beginning of the Silk Road trade network that extended to the Roman Empire, bringing Han items like silk to Rome and Roman goods such as glasswares to China.

From roughly 115 to 60 BC, Han forces fought the Xiongnu over control of the oasis city-states in the Tarim Basin. Han was eventually victorious and established the Protectorate of the Western Regions in 60 BC, which dealt with the region's defense and foreign affairs. The Han also expanded southward. The naval conquest of Nanyue in 111 BC expanded the Han realm into what are now modern Guangdong, Guangxi, and northern Vietnam. Yunnan was brought into the Han realm with the conquest of the Dian Kingdom in 109 BC, followed by parts of the Korean Peninsula with the Han conquest of Gojoseon and colonial establishments of Xuantu Commandery and Lelang Commandery in 108 BC. In China's first known nationwide census taken in 2 AD, the population was registered as having 57,671,400 individuals in 12,366,470 households.

To pay for his military campaigns and colonial expansion, Emperor Wu nationalized several private industries. He created central government monopolies administered largely by former merchants. These monopolies included salt, iron, and liquor production, as well as bronze-coin currency. The liquor monopoly lasted only from 98 to 81 BC, and the salt and iron monopolies were eventually abolished in early Eastern Han. The issuing of coinage remained a central government monopoly throughout the rest of the Han dynasty.

The government monopolies were eventually repealed when a political faction known as the Reformists gained greater influence in the court. The Reformists opposed the Modernist faction that had dominated court politics in Emperor Wu's reign and during the subsequent regency of Huo Guang (d. 68 BC). The Modernists argued for an aggressive and expansionary foreign policy supported by revenues from heavy government intervention in the private economy. The Reformists, however, overturned these policies, favoring a cautious, non-expansionary approach to foreign policy, frugal budget reform, and lower tax-rates imposed on private entrepreneurs.

Wang Mangs reign and civil war

Wang Zhengjun (71 BC – 13 AD) was first empress, then empress dowager, and finally grand empress dowager during the reigns of the Emperors Yuan ( BC), Cheng ( BC), and Ai ( BC), respectively. During this time, a succession of her male relatives held the title of regent. Following the death of Ai, Wang Zhengjun's nephew Wang Mang (45 BC – 23 AD) was appointed regent as Marshall of State on 16 August under Emperor Ping ( AD).

When Ping died on 3 February 6 AD, Ruzi Ying (d. 25 AD) was chosen as the heir and Wang Mang was appointed to serve as acting emperor for the child. Wang promised to relinquish his control to Liu Ying once he came of age. Despite this promise, and against protest and revolts from the nobility, Wang Mang claimed on 10 January that the divine Mandate of Heaven called for the end of the Han dynasty and the beginning of his own: the Xin dynasty (9–23 AD).

Wang Mang initiated a series of major reforms that were ultimately unsuccessful. These reforms included outlawing slavery, nationalizing land to equally distribute between households, and introducing new currencies, a change which debased the value of coinage. Although these reforms provoked considerable opposition, Wang's regime met its ultimate downfall with the massive floods of AD and 11 AD. Gradual silt buildup in the Yellow River had raised its water level and overwhelmed the flood control works. The Yellow River split into two new branches: one emptying to the north and the other to the south of the Shandong Peninsula, though Han engineers managed to dam the southern branch by 70 AD.

The flood dislodged thousands of peasant farmers, many of whom joined roving bandit and rebel groups such as the Red Eyebrows to survive. Wang Mang's armies were incapable of quelling these enlarged rebel groups. Eventually, an insurgent mob forced their way into the Weiyang Palace and killed Wang Mang.

The Gengshi Emperor ( AD), a descendant of Emperor Jing ( BC), attempted to restore the Han dynasty and occupied Chang'an as his capital. However, he was overwhelmed by the Red Eyebrow rebels who deposed, assassinated, and replaced him with the puppet monarch Liu Penzi. Gengshi's distant cousin Liu Xiu, known posthumously as Emperor Guangwu ( AD), after distinguishing himself at the Battle of Kunyang in 23 AD, was urged to succeed Gengshi as emperor.

Under Guangwu's rule the Han Empire was restored. Guangwu made Luoyang his capital in 25 AD, and by 27 AD his officers Deng Yu and Feng Yi had forced the Red Eyebrows to surrender and executed their leaders for treason. From 26 until 36 AD, Emperor Guangwu had to wage war against other regional warlords who claimed the title of emperor; when these warlords were defeated, China reunified under the Han.

The period between the foundation of the Han dynasty and Wang Mang's reign is known as the Western Han (西漢 Xīhàn) or Former Han (前漢 Qiánhàn) (206 BC – 9 AD). During this period the capital was at Chang'an (modern Xi'an). From the reign of Guangwu the capital was moved eastward to Luoyang. The era from his reign until the fall of Han is known as the Eastern Han or Later Han (25–220 AD).

Eastern Han

The Eastern Han (東漢 Dōnghàn), also known as the Later Han (後漢 Hòuhàn), formally began on 5 August AD 25, when Liu Xiu became Emperor Guangwu of Han. During the widespread rebellion against Wang Mang, the state of Goguryeo was free to raid Han's Korean commanderies; Han did not reaffirm its control over the region until AD 30.

The Trưng Sisters of Vietnam rebelled against Han in AD 40. Their rebellion was crushed by Han general Ma Yuan (d. AD 49) in a campaign from AD 42–43. Wang Mang renewed hostilities against the Xiongnu, who were estranged from Han until their leader Bi (比), a rival claimant to the throne against his cousin Punu (蒲奴), submitted to Han as a tributary vassal in AD 50. This created two rival Xiongnu states: the Southern Xiongnu led by Bi, an ally of Han, and the Northern Xiongnu led by Punu, an enemy of Han.

During the turbulent reign of Wang Mang, China lost control over the Tarim Basin, which was conquered by the Northern Xiongnu in AD 63 and used as a base to invade the Hexi Corridor in Gansu. Dou Gu (d. 88 AD) defeated the Northern Xiongnu at the Battle of Yiwulu in AD 73, evicting them from Turpan and chasing them as far as Lake Barkol before establishing a garrison at Hami. After the new Protector General of the Western Regions Chen Mu (d. AD 75) was killed by allies of the Xiongnu in Karasahr and Kucha, the garrison at Hami was withdrawn.

At the Battle of Ikh Bayan in AD 89, Dou Xian (d. AD 92) defeated the Northern Xiongnu chanyu who then retreated into the Altai Mountains. After the Northern Xiongnu fled into the Ili River valley in AD 91, the nomadic Xianbei occupied the area from the borders of the Buyeo Kingdom in Manchuria to the Ili River of the Wusun people. The Xianbei reached their apogee under Tanshihuai (檀石槐) (d. AD 180), who consistently defeated Chinese armies. However, Tanshihuai's confederation disintegrated after his death.

Ban Chao (d. AD 102) enlisted the aid of the Kushan Empire, occupying the area of modern India, Pakistan, Afghanistan, and Tajikistan, to subdue Kashgar and its ally Sogdiana. When a request by Kushan ruler Vima Kadphises for a marriage alliance with the Han was rejected in AD 90, he sent his forces to Wakhan (Afghanistan) to attack Ban Chao. The conflict ended with the Kushans withdrawing because of lack of supplies. In AD 91, the office of Protector General of the Western Regions was reinstated when it was bestowed on Ban Chao.

Foreign travelers to Eastern-Han China include Buddhist monks who translated works into Chinese, such as An Shigao from Parthia, and Lokaksema from Kushan-era Gandhara, India. In addition to tributary relations with the Kushans, the Han Empire received gifts from the Parthian Empire, from a king in modern Burma, from a ruler in Japan, and initiated an unsuccessful mission to Daqin (Rome) in AD 97 with Gan Ying as emissary.

A Roman embassy of Emperor Marcus Aurelius ( AD) is recorded in the Weilüe and Hou Hanshu to have reached the court of Emperor Huan of Han ( AD) in AD 166, yet Rafe de Crespigny asserts that this was most likely a group of Roman merchants. In addition to Roman glasswares and coins found in China, Roman medallions from the reign of Antoninus Pius and his adopted son Marcus Aurelius have been found at Óc Eo in Vietnam. This was near the commandery of Rinan (also Jiaozhi) where Chinese sources claim the Romans first landed, as well as embassies from Tianzhu (in northern India) in the years 159 and 161. Óc Eo is also thought to be the port city "Cattigara" described by Ptolemy in his Geography ( AD) as lying east of the Golden Chersonese (Malay Peninsula) along the Magnus Sinus (i.e. Gulf of Thailand and South China Sea), where a Greek sailor had visited.

Emperor Zhang's ( AD) reign came to be viewed by later Eastern Han scholars as the high point of the dynastic house. Subsequent reigns were increasingly marked by eunuch intervention in court politics and their involvement in the violent power struggles of the imperial consort clans. In 92 AD, with the aid of the eunuch Zheng Zhong (d. 107 AD), Emperor He ( AD) had Empress Dowager Dou (d. 97 AD) put under house arrest and her clan stripped of power. This was in revenge for Dou's purging of the clan of his natural mother—Consort Liang—and then concealing her identity from him. After Emperor He's death, his wife Empress Deng Sui (d. 121 AD) managed state affairs as the regent empress dowager during a turbulent financial crisis and widespread Qiang rebellion that lasted from 107 to 118 AD.

When Empress Dowager Deng died, Emperor An ( AD) was convinced by the accusations of the eunuchs Li Run and Jiang Jing (江京) that Deng and her family had planned to depose him. An dismissed Deng's clan members from office, exiled them and forced many to commit suicide. After An's death, his wife, Empress Dowager Yan (d. 126 AD) placed the child Marquess of Beixiang on the throne in an attempt to retain power within her family. However, palace eunuch Sun Cheng (d. 132 AD) masterminded a successful overthrow of her regime to enthrone Emperor Shun of Han ( AD). Yan was placed under house arrest, her relatives were either killed or exiled, and her eunuch allies were slaughtered. The regent Liang Ji (d. 159 AD), brother of Empress Liang Na (d. 150 AD), had the brother-in-law of Consort Deng Mengnü (later empress) (d. 165 AD) killed after Deng Mengnü resisted Liang Ji's attempts to control her. Afterward, Emperor Huan employed eunuchs to depose Liang Ji, who was then forced to commit suicide.

Students from the Imperial University organized a widespread student protest against the eunuchs of Emperor Huan's court. Huan further alienated the bureaucracy when he initiated grandiose construction projects and hosted thousands of concubines in his harem at a time of economic crisis. Palace eunuchs imprisoned the official Li Ying and his associates from the Imperial University on a dubious charge of treason. In 167 AD, the Grand Commandant Dou Wu (d. 168 AD) convinced his son-in-law, Emperor Huan, to release them. However the emperor permanently barred Li Ying and his associates from serving in office, marking the beginning of the Partisan Prohibitions.

Following Huan's death, Dou Wu and the Grand Tutor Chen Fan (d. 168 AD) attempted a coup d'état against the eunuchs Hou Lan (d. 172 AD), Cao Jie (d. 181 AD), and Wang Fu (王甫). When the plot was uncovered, the eunuchs arrested Empress Dowager Dou (d. 172 AD) and Chen Fan. General Zhang Huan favored the eunuchs. He and his troops confronted Dou Wu and his retainers at the palace gate where each side shouted accusations of treason against the other. When the retainers gradually deserted Dou Wu, he was forced to commit suicide.

Under Emperor Ling ( AD) the eunuchs had the partisan prohibitions renewed and expanded, while also auctioning off top government offices. Many affairs of state were entrusted to the eunuchs Zhao Zhong (d. 189 AD) and Zhang Rang (d. 189 AD) while Emperor Ling spent much of his time roleplaying with concubines and participating in military parades.

End of the Han dynasty

The Partisan Prohibitions were repealed during the Yellow Turban Rebellion and Five Pecks of Rice Rebellion in 184 AD, largely because the court did not want to continue to alienate a significant portion of the gentry class who might otherwise join the rebellions. The Yellow Turbans and Five-Pecks-of-Rice adherents belonged to two different hierarchical Daoist religious societies led by faith healers Zhang Jue (d. 184 AD) and Zhang Lu (d. 216 AD), respectively.

Zhang Lu's rebellion, in modern northern Sichuan and southern Shaanxi, was not quelled until 215 AD. Zhang Jue's massive rebellion across eight provinces was annihilated by Han forces within a year, however the following decades saw much smaller recurrent uprisings. Although the Yellow Turbans were defeated, many generals appointed during the crisis never disbanded their assembled militia forces and used these troops to amass power outside of the collapsing imperial authority.

General-in-Chief He Jin (d. 189 AD), half-brother to Empress He (d. 189 AD), plotted with Yuan Shao (d. 202 AD) to overthrow the eunuchs by having several generals march to the outskirts of the capital. There, in a written petition to Empress He, they demanded the eunuchs' execution. After a period of hesitation, Empress He consented. When the eunuchs discovered this, however, they had her brother He Miao (何苗) rescind the order. The eunuchs assassinated He Jin on September 22, 189 AD.

Yuan Shao then besieged Luoyang's Northern Palace while his brother Yuan Shu (d. 199 AD) besieged the Southern Palace. On September 25 both palaces were breached and approximately two thousand eunuchs were killed. Zhang Rang had previously fled with Emperor Shao ( AD) and his brother Liu Xie—the future Emperor Xian of Han ( AD). While being pursued by the Yuan brothers, Zhang committed suicide by jumping into the Yellow River.

General Dong Zhuo (d. 192 AD) found the young emperor and his brother wandering in the countryside. He escorted them safely back to the capital and was made Minister of Works, taking control of Luoyang and forcing Yuan Shao to flee. After Dong Zhuo demoted Emperor Shao and promoted his brother Liu Xie as Emperor Xian, Yuan Shao led a coalition of former officials and officers against Dong, who burned Luoyang to the ground and resettled the court at Chang'an in May 191 AD. Dong Zhuo later poisoned Emperor Shao.

Dong was killed by his adopted son Lü Bu (d. 198 AD) in a plot hatched by Wang Yun (d. 192 AD). Emperor Xian fled from Chang'an in 195 AD to the ruins of Luoyang. Xian was persuaded by Cao Cao (155–220 AD), then Governor of Yan Province in modern western Shandong and eastern Henan, to move the capital to Xuchang in 196 AD.

Yuan Shao challenged Cao Cao for control over the emperor. Yuan's power was greatly diminished after Cao defeated him at the Battle of Guandu in 200 AD. After Yuan died, Cao killed Yuan Shao's son Yuan Tan (173–205 AD), who had fought with his brothers over the family inheritance. His brothers Yuan Shang and Yuan Xi were killed in 207 AD by Gongsun Kang (d. 221 AD), who sent their heads to Cao Cao.

After Cao's defeat at the naval Battle of Red Cliffs in 208 AD, China was divided into three spheres of influence, with Cao Cao dominating the north, Sun Quan (182–252 AD) dominating the south, and Liu Bei (161–223 AD) dominating the west. Cao Cao died in March 220 AD. By December his son Cao Pi (187–226 AD) had Emperor Xian relinquish the throne to him and is known posthumously as Emperor Wen of Wei. This formally ended the Han dynasty and initiated an age of conflict between three states: Cao Wei, Eastern Wu, and Shu Han.

Culture and society

Social class

In the hierarchical social order, the emperor was at the apex of Han society and government. However the emperor was often a minor, ruled over by a regent such as the empress dowager or one of her male relatives. Ranked immediately below the emperor were the kings who were of the same Liu family clan. The rest of society, including nobles lower than kings and all commoners excluding slaves belonged to one of twenty ranks (ershi gongcheng 二十公乘).

Each successive rank gave its holder greater pensions and legal privileges. The highest rank, of full marquess, came with a state pension and a territorial fiefdom. Holders of the rank immediately below, that of ordinary marquess, received a pension, but had no territorial rule. Officials who served in government belonged to the wider commoner social class and were ranked just below nobles in social prestige. The highest government officials could be enfeoffed as marquesses.

By the Eastern Han period, local elites of unattached scholars, teachers, students, and government officials began to identify themselves as members of a larger, nationwide gentry class with shared values and a commitment to mainstream scholarship. When the government became noticeably corrupt in mid-to-late Eastern Han, many gentrymen even considered the cultivation of morally grounded personal relationships more important than serving in public office.

The farmer, or specifically the small landowner-cultivator, was ranked just below scholars and officials in the social hierarchy. Other agricultural cultivators were of a lower status, such as tenants, wage laborers, and slaves. The Han dynasty made adjustments to slavery in China and saw an increase in agricultural slaves. Artisans, technicians, tradespeople and craftsmen had a legal and socioeconomic status between that of owner-cultivator farmers and common merchants.

State-registered merchants, who were forced by law to wear white-colored clothes and pay high commercial taxes, were considered by the gentry as social parasites with a contemptible status. These were often petty shopkeepers of urban marketplaces; merchants such as industrialists and itinerant traders working between a network of cities could avoid registering as merchants and were often wealthier and more powerful than the vast majority of government officials.

Wealthy landowners, such as nobles and officials, often provided lodging for retainers who provided valuable work or duties, sometimes including fighting bandits or riding into battle. Unlike slaves, retainers could come and go from their master's home as they pleased. Medical physicians, pig breeders, and butchers had a fairly high social status, while occultist diviners, runners, and messengers had low status.

Marriage, gender, and kinship

The Han-era family was patrilineal and typically had four to five nuclear family members living in one household. Multiple generations of extended family members did not occupy the same house, unlike families of later dynasties. According to Confucian family norms, various family members were treated with different levels of respect and intimacy. For example, there were different accepted time frames for mourning the death of a father versus a paternal uncle.

Marriages were highly ritualized, particularly for the wealthy, and included many important steps. The giving of betrothal gifts, known as bridewealth and dowry, were especially important. A lack of either was considered dishonorable and the woman would have been seen not as a wife, but as a concubine. Arranged marriages were normal, with the father's input on his offspring's spouse being considered more important than the mother's.

Monogamous marriages were also normal, although nobles and high officials were wealthy enough to afford and support concubines as additional lovers. Under certain conditions dictated by custom, not law, both men and women were able to divorce their spouses and remarry. However, a woman who had been widowed continued to belong to her husband's family after his death. In order to remarry, the widow would have to be returned to her family in exchange for a ransom fee. Her children would not be allowed to go with her.

Apart from the passing of noble titles or ranks, inheritance practices did not involve primogeniture; each son received an equal share of the family property. Unlike the practice in later dynasties, the father usually sent his adult married sons away with their portions of the family fortune. Daughters received a portion of the family fortune through their marriage dowries, though this was usually much less than the shares of sons. A different distribution of the remainder could be specified in a will, but it is unclear how common this was.

Women were expected to obey the will of their father, then their husband, and then their adult son in old age. However, it is known from contemporary sources that there were many deviations to this rule, especially in regard to mothers over their sons, and empresses who ordered around and openly humiliated their fathers and brothers. Women were exempt from the annual corvée labor duties, but often engaged in a range of income-earning occupations aside from their domestic chores of cooking and cleaning.

The most common occupation for women was weaving clothes for the family, sale at market or for large textile enterprises that employed hundreds of women. Other women helped on their brothers' farms or became singers, dancers, sorceresses, respected medical physicians, and successful merchants who could afford their own silk clothes. Some women formed spinning collectives, aggregating the resources of several different families.

Education, literature, and philosophy

The early Western Han court simultaneously accepted the philosophical teachings of Legalism, Huang-Lao Daoism, and Confucianism in making state decisions and shaping government policy. However, the Han court under Emperor Wu gave Confucianism exclusive patronage. He abolished all academic chairs or erudites (bóshì 博士) not dealing with the Confucian Five Classics in 136 BCE and encouraged nominees for office to receive a Confucian-based education at the Imperial University that he established in 124 BCE.

Unlike the original ideology espoused by Confucius, or Kongzi (551–479 BCE), Han Confucianism in Emperor Wu's reign was the creation of Dong Zhongshu (179–104 BCE). Dong was a scholar and minor official who aggregated the ethical Confucian ideas of ritual, filial piety, and harmonious relationships with five phases and yin-yang cosmologies. Much to the interest of the ruler, Dong's synthesis justified the imperial system of government within the natural order of the universe.

The Imperial University grew in importance as the student body grew to over 30,000 by the 2nd century CE. A Confucian-based education was also made available at commandery-level schools and private schools opened in small towns, where teachers earned respectable incomes from tuition payments. Schools were established in far southern regions where standard Chinese texts were used to assimilate the local populace.

Some important texts were created and studied by scholars. Philosophical works written by Yang Xiong (53 BCE – 18 CE), Huan Tan (43 BCE – 28 CE), Wang Chong (27–100 CE), and Wang Fu (78–163 CE) questioned whether human nature was innately good or evil and posed challenges to Dong's universal order. The Records of the Grand Historian by Sima Tan (d. 110 BCE) and his son Sima Qian (145–86 BCE) established the standard model for all of imperial China's Standard Histories, such as the Book of Han written by Ban Biao (3–54 CE), his son Ban Gu (32–92 CE), and his daughter Ban Zhao (45–116 CE). There were dictionaries such as the Shuowen Jiezi by Xu Shen ( – CE) and the Fangyan by Yang Xiong.

Biographies on important figures were written by various gentrymen. Han dynasty poetry was dominated by the fu genre, which achieved its greatest prominence during the reign of Emperor Wu.

Law and order

Han scholars such as Jia Yi (201–169 BCE) portrayed the previous Qin dynasty as a brutal regime. However, archeological evidence from Zhangjiashan and Shuihudi reveal that many of the statutes in the Han law code compiled by Chancellor Xiao He (d. 193 BCE) were derived from Qin law.

Various cases for rape, physical abuse and murder were prosecuted in court. Women, although usually having fewer rights by custom, were allowed to level civil and criminal charges against men. While suspects were jailed, convicted criminals were never imprisoned. Instead, punishments were commonly monetary fines, periods of forced hard labor for convicts, and the penalty of death by beheading. Early Han punishments of torturous mutilation were borrowed from Qin law. A series of reforms abolished mutilation punishments with progressively less-severe beatings by the bastinado.

Acting as a judge in lawsuits was one of many duties of the county magistrate and Administrators of commanderies. Complex, high-profile or unresolved cases were often deferred to the Minister of Justice in the capital or even the emperor. In each Han county was several districts, each overseen by a chief of police. Order in the cities was maintained by government officers in the marketplaces and constables in the neighborhoods.

Food

The most common staple crops consumed during Han were wheat, barley, foxtail millet, proso millet, rice, and beans. Commonly eaten fruits and vegetables included chestnuts, pears, plums, peaches, melons, apricots, strawberries, red bayberries, jujubes, calabash, bamboo shoots, mustard plant, and taro. Domesticated animals that were also eaten included chickens, Mandarin ducks, geese, cows, sheep, pigs, camels, and dogs (various types were bred specifically for food, while most were used as pets). Turtles and fish were taken from streams and lakes. Commonly hunted game, such as owl, pheasant, magpie, sika deer, and Chinese bamboo partridge were consumed. Seasonings included sugar, honey, salt, and soy sauce. Beer and wine were regularly consumed.

Clothing

The types of clothing worn and the materials used during the Han period depended upon social class. Wealthy folk could afford silk robes, skirts, socks, and mittens, coats made of badger or fox fur, duck plumes, and slippers with inlaid leather, pearls, and silk lining. Peasants commonly wore clothes made of hemp, wool, and ferret skins.

Religion, cosmology, and metaphysics

Families throughout Han China made ritual sacrifices of animals and food to deities, spirits, and ancestors at temples and shrines. They believed that these items could be utilized by those in the spiritual realm. It was thought that each person had a two-part soul: the spirit-soul (hun 魂) which journeyed to the afterlife paradise of immortals (xian), and the body-soul (po 魄) which remained in its grave or tomb on earth and was only reunited with the spirit-soul through a ritual ceremony.

In addition to his many other roles, the emperor acted as the highest priest in the land who made sacrifices to Heaven, the main deities known as the Five Powers, and the spirits (shen 神) of mountains and rivers. It was believed that the three realms of Heaven, Earth, and Mankind were linked by natural cycles of yin and yang and the five phases. If the emperor did not behave according to proper ritual, ethics, and morals, he could disrupt the fine balance of these cosmological cycles and cause calamities such as earthquakes, floods, droughts, epidemics, and swarms of locusts.

It was believed that immortality could be achieved if one reached the lands of the Queen Mother of the West or Mount Penglai. Han-era Daoists assembled into small groups of hermits who attempted to achieve immortality through breathing exercises, sexual techniques and use of medical elixirs.

By the 2nd century CE, Daoists formed large hierarchical religious societies such as the Way of the Five Pecks of Rice. Its followers believed that the sage-philosopher Laozi was a holy prophet who would offer salvation and good health if his devout followers would confess their sins, ban the worship of unclean gods who accepted meat sacrifices and chant sections of the Daodejing.

Buddhism first entered Imperial China through the Silk Road during the Eastern Han, and was first mentioned in 65 CE. Liu Ying (d. 71 CE), a half-brother to Emperor Ming of Han ( CE), was one of its earliest Chinese adherents, although Chinese Buddhism at this point was heavily associated with Huang-Lao Daoism. China's first known Buddhist temple, the White Horse Temple, was constructed outside the wall of the capital, Luoyang, during Emperor Ming's reign. Important Buddhist canons were translated into Chinese during the 2nd century CE, including the Sutra of Forty-two Chapters, Perfection of Wisdom, Shurangama Sutra, and Pratyutpanna Sutra.

Government and politics

Central government

In Han government, the emperor was the supreme judge and lawgiver, the commander-in-chief of the armed forces and sole designator of official nominees appointed to the top posts in central and local administrations; those who earned a 600-bushel salary-rank or higher. Theoretically, there were no limits to his power.

However, state organs with competing interests and institutions such as the court conference (tíngyì 廷議)—where ministers were convened to reach majority consensus on an issue—pressured the emperor to accept the advice of his ministers on policy decisions. If the emperor rejected a court conference decision, he risked alienating his high ministers. Nevertheless, emperors sometimes did reject the majority opinion reached at court conferences.

Below the emperor were his cabinet members known as the Three Councillors of State (Sān gōng 三公). These were the Chancellor or Minister over the Masses (Chéngxiāng 丞相 or Dà sìtú 大司徒), the Imperial Counselor or Excellency of Works (Yùshǐ dàfū 御史大夫 or Dà sìkōng 大司空), and Grand Commandant or Grand Marshal (Tàiwèi 太尉 or Dà sīmǎ 大司馬).

The Chancellor, whose title was changed to 'Minister over the Masses' in 8 BC, was chiefly responsible for drafting the government budget. The Chancellor's other duties included managing provincial registers for land and population, leading court conferences, acting as judge in lawsuits and recommending nominees for high office. He could appoint officials below the salary-rank of 600 bushels.

The Imperial Counselor's chief duty was to conduct disciplinary procedures for officials. He shared similar duties with the Chancellor, such as receiving annual provincial reports. However, when his title was changed to Minister of Works in 8 BC, his chief duty became oversight of public works projects.

The Grand Commandant, whose title was changed to Grand Marshal in 119 BC before reverting to Grand Commandant in 51 AD, was the irregularly posted commander of the military and then regent during the Western Han period. In the Eastern Han era he was chiefly a civil official who shared many of the same censorial powers as the other two Councillors of State.

Ranked below the Three Councillors of State were the Nine Ministers (Jiǔ qīng 九卿), who each headed a specialized ministry. The Minister of Ceremonies (Tàicháng 太常) was the chief official in charge of religious rites, rituals, prayers and the maintenance of ancestral temples and altars. The Minister of the Household (Guāng lù xūn 光祿勳) was in charge of the emperor's security within the palace grounds, external imperial parks and wherever the emperor made an outing by chariot.

The Minister of the Guards (Wèiwèi 衛尉) was responsible for securing and patrolling the walls, towers, and gates of the imperial palaces. The Minister Coachman (Tàipú 太僕) was responsible for the maintenance of imperial stables, horses, carriages and coach-houses for the emperor and his palace attendants, as well as the supply of horses for the armed forces. The Minister of Justice (Tíngwèi 廷尉) was the chief official in charge of upholding, administering, and interpreting the law. The Minister Herald (Dà hónglú 大鴻臚) was the chief official in charge of receiving honored guests at the imperial court, such as nobles and foreign ambassadors.

The Minister of the Imperial Clan (Zōngzhèng 宗正) oversaw the imperial court's interactions with the empire's nobility and extended imperial family, such as granting fiefs and titles. The Minister of Finance (Dà sìnóng 大司農) was the treasurer for the official bureaucracy and the armed forces who handled tax revenues and set standards for units of measurement. The Minister Steward (Shǎofǔ 少府) served the emperor exclusively, providing him with entertainment and amusements, proper food and clothing, medicine and physical care, valuables and equipment.

Local government

The Han empire, excluding kingdoms and marquessates, was divided, in descending order of size, into political units of provinces, commanderies, and counties. A county was divided into several districts (xiang 鄉), the latter composed of a group of hamlets (li 里), each containing about a hundred families.

The heads of provinces, whose official title was changed from Inspector to Governor and vice versa several times during Han, were responsible for inspecting several commandery-level and kingdom-level administrations. On the basis of their reports, the officials in these local administrations would be promoted, demoted, dismissed or prosecuted by the imperial court.

A governor could take various actions without permission from the imperial court. The lower-ranked inspector had executive powers only during times of crisis, such as raising militias across the commanderies under his jurisdiction to suppress a rebellion.

A commandery consisted of a group of counties, and was headed by an Administrator. He was the top civil and military leader of the commandery and handled defense, lawsuits, seasonal instructions to farmers and recommendations of nominees for office sent annually to the capital in a quota system first established by Emperor Wu. The head of a large county of about 10,000 households was called a Prefect, while the heads of smaller counties were called Chiefs, and both could be referred to as Magistrates. A Magistrate maintained law and order in his county, registered the populace for taxation, mobilized commoners for annual corvée duties, repaired schools and supervised public works.

Kingdoms and marquessates

Kingdoms—roughly the size of commanderies—were ruled exclusively by the emperor's male relatives as semi-autonomous fiefdoms. Before 157 BC some kingdoms were ruled by non-relatives, granted to them in return for their services to Emperor Gaozu. The administration of each kingdom was very similar to that of the central government. Although the emperor appointed the Chancellor of each kingdom, kings appointed all the remaining civil officials in their fiefs.

However, in 145 BC, after several insurrections by the kings, Emperor Jing removed the kings' rights to appoint officials whose salaries were higher than 400 bushels. The Imperial Counselors and Nine Ministers (excluding the Minister Coachman) of every kingdom were abolished, although the Chancellor was still appointed by the central government.

With these reforms, kings were reduced to being nominal heads of their fiefs, gaining a personal income from only a portion of the taxes collected in their kingdom. Similarly, the officials in the administrative staff of a full marquess's fief were appointed by the central government. A marquess's Chancellor was ranked as the equivalent of a county Prefect. Like a king, the marquess collected a portion of the tax revenues in his fief as personal income.

Up until the reign of Emperor Jing of Han, the Emperors of the Han had great difficulty bringing the vassal kings under control, as kings often switched their allegiance to the Xiongnu Chanyu whenever threatened by Imperial attempts to centralize power. Within the seven years of Han Gaozu's reign, three vassal kings and one marquess either defected to or allied with the Xiongnu. Even imperial princes in control of fiefdoms would sometimes invite the Xiongnu to invade in response to threats by the Emperor to remove their power. The Han emperors moved to secure a treaty with the Chanyu to demarcate authority between them, recognizing each other as the "two masters" (兩主), the sole representatives of their respective peoples, cemented with a marriage alliance (heqin), before eliminating the rebellious vassal kings in 154 BC. This prompted some vassal kings of the Xiongnu to switch their allegiance to the Han emperor from 147 BC. Han court officials were initially hostile to the idea of disrupting the status quo and expanding into the Xiongnu steppe territory. The surrendered Xiongnu were integrated into a parallel military and political structure under the Han Emperor, and opened the avenue for the Han dynasty to challenge the Xiongnu cavalry on the steppe. This also introduced the Han to the interstate networks in the Tarim Basin (Xinjiang), allowing for the expansion of the Han dynasty from a limited regional state to a universalist and cosmopolitan empire through further marriage alliances with another steppe power, the Wusun.

Military

At the beginning of the Han dynasty, every male commoner aged twenty-three was liable for conscription into the military. The minimum age for the military draft was reduced to twenty after Emperor Zhao's ( BC) reign. Conscripted soldiers underwent one year of training and one year of service as non-professional soldiers. The year of training was served in one of three branches of the armed forces: infantry, cavalry or navy. Soldiers who completed their term of service still needed to train to maintain their skill because they were subject to annual military readiness inspections and could be called up for future service - until this practice was discontinued after 30 AD with the abolishment of much of the conscription system. The year of active service was served either on the frontier, in a king's court or under the Minister of the Guards in the capital. A small professional (full time career) standing army was stationed near the capital.

During the Eastern Han, conscription could be avoided if one paid a commutable tax. The Eastern Han court favored the recruitment of a volunteer army. The volunteer army comprised the Southern Army (Nanjun 南軍), while the standing army stationed in and near the capital was the Northern Army (Beijun 北軍). Led by Colonels (Xiaowei 校尉), the Northern Army consisted of five regiments, each composed of several thousand soldiers. When central authority collapsed after 189 AD, wealthy landowners, members of the aristocracy/nobility, and regional military-governors relied upon their retainers to act as their own personal troops. The latter were known as 部曲, a special social class in Chinese history.

During times of war, the volunteer army was increased, and a much larger militia was raised across the country to supplement the Northern Army. In these circumstances, a General (Jiangjun 將軍) led a division, which was divided into regiments led by Colonels and sometimes Majors (Sima 司馬). Regiments were divided into companies and led by Captains. Platoons were the smallest units of soldiers.

Economy

Currency

The Han dynasty inherited the ban liang coin type from the Qin. In the beginning of the Han, Emperor Gaozu closed the government mint in favor of private minting of coins. This decision was reversed in 186 BC by his widow Grand Empress Dowager Lü Zhi (d. 180 BC), who abolished private minting. In 182 BC, Lü Zhi issued a bronze coin that was much lighter in weight than previous coins. This caused widespread inflation that was not reduced until 175 BC when Emperor Wen allowed private minters to manufacture coins that were precisely 2.6 g (0.09 oz) in weight.

In 144 BC Emperor Jing abolished private minting in favor of central-government and commandery-level minting; he also introduced a new coin. Emperor Wu introduced another in 120 BC, but a year later he abandoned the ban liangs entirely in favor of the wuzhu (五銖) coin, weighing 3.2 g (0.11 oz). The wuzhu became China's standard coin until the Tang dynasty (618–907 AD). Its use was interrupted briefly by several new currencies introduced during Wang Mang's regime until it was reinstated in 40 AD by Emperor Guangwu.

Since commandery-issued coins were often of inferior quality and lighter weight, the central government closed commandery mints and monopolized the issue of coinage in 113 BC. This central government issuance of coinage was overseen by the Superintendent of Waterways and Parks, this duty being transferred to the Minister of Finance during Eastern Han.

Taxation and property

Aside from the landowner's land tax paid in a portion of their crop yield, the poll tax and property taxes were paid in coin cash. The annual poll tax rate for adult men and women was 120 coins and 20 coins for minors. Merchants were required to pay a higher rate of 240 coins. The poll tax stimulated a money economy that necessitated the minting of over 28,000,000,000 coins from 118 BC to 5 AD, an average of 220,000,000 coins a year.

The widespread circulation of coin cash allowed successful merchants to invest money in land, empowering the very social class the government attempted to suppress through heavy commercial and property taxes. Emperor Wu even enacted laws which banned registered merchants from owning land, yet powerful merchants were able to avoid registration and own large tracts of land.

The small landowner-cultivators formed the majority of the Han tax base; this revenue was threatened during the latter half of Eastern Han when many peasants fell into debt and were forced to work as farming tenants for wealthy landlords. The Han government enacted reforms in order to keep small landowner-cultivators out of debt and on their own farms. These reforms included reducing taxes, temporary remissions of taxes, granting loans and providing landless peasants temporary lodging and work in agricultural colonies until they could recover from their debts.

In 168 BC, the land tax rate was reduced from one-fifteenth of a farming household's crop yield to one-thirtieth, and later to a one-hundredth of a crop yield for the last decades of the dynasty. The consequent loss of government revenue was compensated for by increasing property taxes.

The labor tax took the form of conscripted labor for one month per year, which was imposed upon male commoners aged fifteen to fifty-six. This could be avoided in Eastern Han with a commutable tax, since hired labor became more popular.

Private manufacture and government monopolies

In the early Western Han, a wealthy salt or iron industrialist, whether a semi-autonomous king or wealthy merchant, could boast funds that rivaled the imperial treasury and amass a peasant workforce of over a thousand. This kept many peasants away from their farms and denied the government a significant portion of its land tax revenue. To eliminate the influence of such private entrepreneurs, Emperor Wu nationalized the salt and iron industries in 117 BC and allowed many of the former industrialists to become officials administering the state monopolies. By Eastern Han times, the central government monopolies were repealed in favor of production by commandery and county administrations, as well as private businessmen.

Liquor was another profitable private industry nationalized by the central government in 98 BC. However, this was repealed in 81 BC and a property tax rate of two coins for every 0.2 L (0.05 gallons) was levied for those who traded it privately. By 110 BC Emperor Wu also interfered with the profitable trade in grain when he eliminated speculation by selling government-stored grain at a lower price than demanded by merchants. Apart from Emperor Ming's creation of a short-lived Office for Price Adjustment and Stabilization, which was abolished in 68 AD, central-government price control regulations were largely absent during the Eastern Han.

Science and technology

The Han dynasty was a unique period in the development of premodern Chinese science and technology, comparable to the level of scientific and technological growth during the Song dynasty (960–1279).

Writing materials

In the 1st millennium BC, typical ancient Chinese writing materials were bronzewares, animal bones, and bamboo slips or wooden boards. By the beginning of the Han dynasty, the chief writing materials were clay tablets, silk cloth, hemp paper, and rolled scrolls made from bamboo strips sewn together with hempen string; these were passed through drilled holes and secured with clay stamps.

The oldest known Chinese piece of hempen paper dates to the 2nd century BC. The standard papermaking process was invented by Cai Lun (AD 50–121) in 105. The oldest known surviving piece of paper with writing on it was found in the ruins of a Han watchtower that had been abandoned in AD 110, in Inner Mongolia.

Metallurgy and agriculture

Evidence suggests that blast furnaces, that convert raw iron ore into pig iron, which can be remelted in a cupola furnace to produce cast iron by means of a cold blast and hot blast, were operational in China by the late Spring and Autumn period (722–481 BC). The bloomery was nonexistent in ancient China; however, the Han-era Chinese produced wrought iron by injecting excess oxygen into a furnace and causing decarburization. Cast iron and pig iron could be converted into wrought iron and steel using a fining process.

The Han dynasty Chinese used bronze and iron to make a range of weapons, culinary tools, carpenters' tools and domestic wares. A significant product of these improved iron-smelting techniques was the manufacture of new agricultural tools. The three-legged iron seed drill, invented by the 2nd century BC, enabled farmers to carefully plant crops in rows instead of casting seeds out by hand. The heavy moldboard iron plow, also invented during the Han dynasty, required only one man to control it, two oxen to pull it. It had three plowshares, a seed box for the drills, a tool which turned down the soil and could sow roughly 45,730 m2 (11.3 acres) of land in a single day.

To protect crops from wind and drought, the grain intendant Zhao Guo (趙過) created the alternating fields system (daitianfa 代田法) during Emperor Wu's reign. This system switched the positions of furrows and ridges between growing seasons. Once experiments with this system yielded successful results, the government officially sponsored it and encouraged peasants to use it. Han farmers also used the pit field system ( 凹田) for growing crops, which involved heavily fertilized pits that did not require plows or oxen and could be placed on sloping terrain. In southern and small parts of central Han-era China, paddy fields were chiefly used to grow rice, while farmers along the Huai River used transplantation methods of rice production.

Structural and geotechnical engineering

Timber was the chief building material during the Han dynasty; it was used to build palace halls, multi-story residential towers and halls and single-story houses. Because wood decays rapidly, the only remaining evidence of Han wooden architecture is a collection of scattered ceramic roof tiles. The oldest surviving wooden halls in China date to the Tang dynasty (AD 618–907). Architectural historian Robert L. Thorp points out the scarcity of Han-era archeological remains, and claims that often unreliable Han-era literary and artistic sources are used by historians for clues about lost Han architecture.

Though Han wooden structures decayed, some Han-dynasty ruins made of brick, stone, and rammed earth remain intact. This includes stone pillar-gates, brick tomb chambers, rammed-earth city walls, rammed-earth and brick beacon towers, rammed-earth sections of the Great Wall, rammed-earth platforms where elevated halls once stood, and two rammed-earth castles in Gansu. The ruins of rammed-earth walls that once surrounded the capitals Chang'an and Luoyang still stand, along with their drainage systems of brick arches, ditches, and ceramic water pipes. Monumental stone pillar-gates, twenty-nine of which survive from the Han period, formed entrances of walled enclosures at shrine and tomb sites. These pillars feature artistic imitations of wooden and ceramic building components such as roof tiles, eaves, and balustrades.

The courtyard house is the most common type of home portrayed in Han artwork. Ceramic architectural models of buildings, like houses and towers, were found in Han tombs, perhaps to provide lodging for the dead in the afterlife. These provide valuable clues about lost wooden architecture. The artistic designs found on ceramic roof tiles of tower models are in some cases exact matches to Han roof tiles found at archeological sites.

Over ten Han-era underground tombs have been found, many of them featuring archways, vaulted chambers, and domed roofs. Underground vaults and domes did not require buttress supports since they were held in place by earthen pits. The use of brick vaults and domes in aboveground Han structures is unknown.

From Han literary sources, it is known that wooden-trestle beam bridges, arch bridges, simple suspension bridges, and floating pontoon bridges existed in Han China. However, there are only two known references to arch bridges in Han literature, and only a single Han relief sculpture in Sichuan depicts an arch bridge.

Underground mine shafts, some reaching depths over , were created for the extraction of metal ores. Borehole drilling and derricks were used to lift brine to iron pans where it was distilled into salt. The distillation furnaces were heated by natural gas funneled to the surface through bamboo pipelines. These boreholes perhaps reached a depth of 600 m (2000 ft).

File:登封汉代少室阙.jpg|A pair of stone-carved que (闕) located at the temple of Mount Song in Dengfeng. (Eastern Han dynasty.)

File:幽州書佐秦君石闕 17.jpg|A pair of Han period stone-carved que (闕) located at Babaoshan, Beijing.

File:Gao Yi Que2.jpg|A stone-carved pillar-gate, or que (闕), 6 m (20 ft) in total height, located at the tomb of Gao Yi in Ya'an. (Eastern Han dynasty.)

File:Eastern Han tomb, Luoyang 2.jpg|An Eastern-Han vaulted tomb chamber at Luoyang made of small bricks

Mechanical and hydraulic engineering

Han-era mechanical engineering comes largely from the choice observational writings of sometimes-disinterested Confucian scholars who generally considered scientific and engineering endeavors to be far beneath them. Professional artisan-engineers (jiang 匠) did not leave behind detailed records of their work. Han scholars, who often had little or no expertise in mechanical engineering, sometimes provided insufficient information on the various technologies they described. Nevertheless, some Han literary sources provide crucial information.

For example, in 15 BC the philosopher and poet Yang Xiong described the invention of the belt drive for a quilling machine, which was of great importance to early textile manufacturing. The inventions of mechanical engineer and craftsman Ding Huan are mentioned in the Miscellaneous Notes on the Western Capital. Around AD 180, Ding created a manually operated rotary fan used for air conditioning within palace buildings. Ding also used gimbals as pivotal supports for one of his incense burners and invented the world's first known zoetrope lamp.

Modern archeology has led to the discovery of Han artwork portraying inventions which were otherwise absent in Han literary sources. As observed in Han miniature tomb models, but not in literary sources, the crank handle was used to operate the fans of winnowing machines that separated grain from chaff. The odometer cart, invented during Han, measured journey lengths, using mechanical figures banging drums and gongs to indicate each distance traveled. This invention is depicted in Han artwork by the 2nd century, yet detailed written descriptions were not offered until the 3rd century.

Modern archeologists have also unearthed specimens of devices used during the Han dynasty, for example a pair of sliding metal calipers used by craftsmen for making minute measurements. These calipers contain inscriptions of the exact day and year they were manufactured. These tools are not mentioned in any Han literary sources.

The waterwheel appeared in Chinese records during the Han. As mentioned by Huan Tan about AD 20, they were used to turn gears that lifted iron trip hammers, and were used in pounding, threshing and polishing grain. However, there is no sufficient evidence for the watermill in China until about the 5th century. The Nanyang Commandery Administrator, mechanical engineer, and metallurgist Du Shi (d. 38 AD) created a waterwheel-powered reciprocator that worked the bellows for the smelting of iron. Waterwheels were also used to power chain pumps that lifted water to raised irrigation ditches. The chain pump was first mentioned in China by the philosopher Wang Chong in his 1st-century Balanced Discourse.

The armillary sphere, a three-dimensional representation of the movements in the celestial sphere, was invented in Han China by the 1st century BC. Using a water clock, waterwheel and a series of gears, the Court Astronomer Zhang Heng (AD 78–139) was able to mechanically rotate his metal-ringed armillary sphere. To address the problem of slowed timekeeping in the pressure head of the inflow water clock, Zhang was the first in China to install an additional tank between the reservoir and inflow vessel.

Zhang also invented a device he termed an "earthquake weathervane" ( 候風地動儀), which the British biochemist, sinologist, and historian Joseph Needham described as "the ancestor of all seismographs". This device was able to detect the exact cardinal or ordinal direction of earthquakes from hundreds of kilometers away. It employed an inverted pendulum that, when disturbed by ground tremors, would trigger a set of gears that dropped a metal ball from one of eight dragon mouths (representing all eight directions) into a metal toad's mouth.

The account of this device in the Book of the Later Han describes how, on one occasion, one of the metal balls was triggered without any of the observers feeling a disturbance. Several days later, a messenger arrived bearing news that an earthquake had struck in Longxi Commandery (in modern Gansu Province), the direction the device had indicated, which forced the officials at court to admit the efficacy of Zhang's device.

File:Winnowing machine and tilt hammer.JPG|A Han-dynasty pottery model of two men operating a winnowing machine with a crank handle and a tilt hammer used to pound grain.

File:EastHanSeismograph.JPG|A modern replica of Zhang Heng's seismometer

Mathematics

Three Han mathematical treatises still exist. These are the Book on Numbers and Computation, the Arithmetical Classic of the Gnomon and the Circular Paths of Heaven and the Nine Chapters on the Mathematical Art. Han-era mathematical achievements include solving problems with right-angle triangles, square roots, cube roots, and matrix methods, finding more accurate approximations for pi, providing mathematical proof of the Pythagorean theorem, use of the decimal fraction, Gaussian elimination to solve linear equations, and continued fractions to find the roots of equations.

One of the Han's greatest mathematical advancements was the world's first use of negative numbers. Negative numbers first appeared in the Nine Chapters on the Mathematical Art as black counting rods, where positive numbers were represented by red counting rods. Negative numbers were also used by the Greek mathematician Diophantus around AD 275, and in the 7th-century Bakhshali manuscript of Gandhara, South Asia, but were not widely accepted in Europe until the 16th century.

The Han applied mathematics to various diverse disciplines. In musical tuning, Jing Fang (78–37 BC) realized that 53 perfect fifths was approximate to 31 octaves while creating a musical scale of 60 tones, calculating the difference at 177147⁄176776 (the same value of 53 equal temperament discovered by the German mathematician Nicholas Mercator 1620–1687, i.e. 353/284).

Astronomy

Mathematics were essential in drafting the astronomical calendar, a lunisolar calendar that used the Sun and Moon as time-markers throughout the year. During the spring and autumn periods of the 5th century BC, the Chinese established the Sifen calendar (古四分曆), which measured the tropical year at 365.25 days. This was replaced in 104 BC with the Taichu calendar (太初曆) that measured the tropical year at (~ 365.25016) days and the lunar month at days. However, Emperor Zhang later reinstated the Sifen calendar.

Han Chinese astronomers made star catalogues and detailed records of comets that appeared in the night sky, including recording the 12 BC appearance of the comet now known as Halley's Comet.

Han dynasty astronomers adopted a geocentric model of the universe, theorizing that it was shaped like a sphere surrounding the earth in the center. They assumed that the Sun, Moon, and planets were spherical and not disc-shaped. They also thought that the illumination of the Moon and planets was caused by sunlight, that lunar eclipses occurred when the Earth obstructed sunlight falling onto the Moon, and that a solar eclipse occurred when the Moon obstructed sunlight from reaching the Earth. Although others disagreed with his model, Wang Chong accurately described the water cycle of the evaporation of water into clouds.

Cartography, ships, and vehicles

Evidence found in Chinese literature, and archeological evidence, show that cartography existed in China before the Han. Some of the earliest Han maps discovered were ink-penned silk maps found amongst the Mawangdui Silk Texts in a 2nd-century-BC tomb. The general Ma Yuan created the world's first known raised-relief map from rice in the 1st century. This date could be revised if the tomb of Emperor Qin Shi Huang is excavated and the account in the Records of the Grand Historian concerning a model map of the empire is proven to be true.

Although the use of the graduated scale and grid reference for maps was not thoroughly described until the published work of Pei Xiu (AD 224–271), there is evidence that in the early 2nd century, cartographer Zhang Heng was the first to use scales and grids for maps.

Han dynasty Chinese sailed in a variety of ships different from those of previous eras, such as the tower ship. The junk design was developed and realized during the Han era. Junk ships featured a square-ended bow and stern, a flat-bottomed hull or carvel-shaped hull with no keel or sternpost, and solid transverse bulkheads in the place of structural ribs found in Western vessels. Moreover, Han ships were the first in the world to be steered using a rudder at the stern, in contrast to the simpler steering oar used for riverine transport, allowing them to sail on the high seas.

Although ox-carts and chariots were previously used in China, the wheelbarrow was first used in Han China in the 1st century BC. Han artwork of horse-drawn chariots shows that the Warring-States-Era heavy wooden yoke placed around a horse's chest was replaced by the softer breast strap. Later, during the Northern Wei (386–534), the fully developed horse collar was invented.

File:Western Han Mawangdui Silk Map.JPG|An early Western Han dynasty silk map found in tomb 3 of Mawangdui, depicting the Kingdom of Changsha and Kingdom of Nanyue in southern China (note: the south direction is oriented at the top).

File:Eastern Han pottery boat.JPG|An Eastern Han dynasty pottery boat model with a steering rudder at the stern and anchor at the bow.

Medicine

Han-era medical physicians believed that the human body was subject to the same forces of nature that governed the greater universe, namely the cosmological cycles of yin and yang and the five phases. Each organ of the body was associated with a particular phase. Illness was viewed as a sign that qi or "vital energy" channels leading to a certain organ had been disrupted. Thus, Han-era physicians prescribed medicine that was believed to counteract this imbalance.

For example, since the wood phase was believed to promote the fire phase, medicinal ingredients associated with the wood phase could be used to heal an organ associated with the fire phase. Besides dieting, Han physicians also prescribed moxibustion, acupuncture, and calisthenics as methods of maintaining one's health. When surgery was performed by the Chinese physician Hua Tuo (d. AD 208), he used anesthesia to numb his patients' pain and prescribed a rubbing ointment that allegedly sped the process of healing surgical wounds. Whereas the physician Zhang Zhongjing ( – ) is known to have written the Shanghan lun ("Dissertation on Typhoid Fever"), it is thought that both he and Hua Tuo collaborated in compiling the Shennong Ben Cao Jing medical text.