生平

太原起兵

隋大業十三年（公元617年），李淵時任太原留守，李建成作為長兄攜李元吉等家屬在河東居住，李建成受李淵之命在河東秘密結交英才。李世民與劉文靜首次參與策劃，勸父親起兵。《大唐創業起居注》則說起兵為李淵本意：大業九年（公元613年），李淵就已有建立帝業的念頭，在涿郡與楊廣近臣宇文士及密謀，但因時機尚未成熟而暫且隱忍。大業十二年（公元616年），李淵被委任太原留守，暗自高興，認為這是上天的意思。 大業十三年（公元617年）正月，李淵決心起兵，但顧及李建成等家眷尚在河東。按《大唐創業起居注》記載，並不是李世民策劃和勸說李淵，而是李淵主動對李世民說：「隋歷將盡，吾家繼膺符命，不早起兵者，顧爾兄弟未集耳。今遭羑里之厄，爾昆季須會盟津之師，不得同受孥戮，家破身亡，為英雄所笑。」

李淵以勾結突厥為由，剷除了隋煬帝派來監視他的王威和高君雅，準備于晉陽起兵。 李淵派使者與晉陽北面的突厥結盟，以保後方的安全穩定。但是突厥要李淵脫離隋楊政權，自立為天子，李淵不願答應。儘管劉文靜等人屢次勸說李淵卻並策劃了「興國寺兵諫」，但是李淵仍不妥協。大業十三年（公元617年）五月，李淵密召李建成攜第四子李元吉等家眷從河東到太原。此行路途艱險，又有隋兵追捕，李建成的一個弟弟李智雲便死在路上。李建成的到來，棋局頓活，一直慫恿李淵起兵的裴寂、劉文靜等人即刻邀建成、世民一同去「請(李淵)依伊尹放太甲，霍光廢昌邑故事，廢皇帝而立代王，興義兵以檄郡縣，改旗幟以示突厥，師出有名，以輯夷夏」。 這個建議馬上被李淵接受。在隨後兵變全程，每逢軍政要事，李淵必與李建成等相商以定。李建成參與起兵的戰略制訂和組織領導工作。

後李建成和李世民隨李淵西征長安，李元吉守太原。義軍未經訓練，建成立整肅三軍。路上的水果蔬菜，非買不食。如有人竊取者，則賠錢，亦不追究所竊之人。百姓贈送蔬食壺漿者，也與將士們一同分享。對贈送的酒肉則不接受，說：「此隋法也，吾不敢。」 至西河城下，李建成親自前往安撫，百姓紛紛來投，只有郡丞高德儒不肯歸降，李建成于是率軍攻打，郡司法書佐朱知瑾從城上將李建成兵馬引進城中，生擒高德儒後斬首，其他人全部赦免。建成平定西河，往返只用了九天時間。李淵贊：「以此用兵，天下橫行可也。」封隴西公，為左領軍大都督。

同年七月，進圖關中，駐軍賈胡堡。八月，李建成建議開始進兵霍邑，李淵擔心霍邑守將宋老生堅守不戰。李建成認為宋老生雖然之前可以平定盜賊，其人出身寒微，有勇無謀，可以引誘他出戰。李淵派幾百個騎兵往霍邑城東，在距城五六里的地方安營，等待步兵。李建成與李世民各只率領幾十個騎兵直到霍邑城下巡視。李淵又將部下分為十幾隊從城東南巡至西南，做出好像要安營又要攻城的樣子，讓殷開山率領後軍開始進軍。宋老生見城下打算安營的兵馬數量不多，李淵後軍尚未前來，于是將三萬人一分為二，自己帶人從東門殺出，另一隊從南門殺出。李淵擔心宋老生不會離城太遠，讓李建成率領左軍，李世民率領右軍，斷掉宋老生的回城之路，李淵自己率軍假裝撤退，宋老生見李淵撤軍，以為是李淵怕了，引軍向前，在距城一里處列陣。殷開山率領步兵前軍列陣，後軍相繼而至。還沒交戰，李建成與李世民率軍作出大攻霍邑東門南門的樣子，李淵放出謠言說宋老生已被斬首，宋老生兵馬聽到後，捨棄兵仗四散奔走。城門又被李建成、李世民所堵，宋老生無法回城，城上人放下繩子想要將宋老生拉上去，軍頭盧君諤趁機將宋老生斬殺。（此處《大唐創業起居注》與《舊唐書》 不一致，《舊唐書》稱載李淵被宋老生擊敗，李建成墜馬，此戰皆由李世民一人完成。）

九月，李建成率領劉文靜等數萬軍隊拒守潼關，兼守永豐倉，以防止屈突通河東駐軍來追擊，慰撫使竇軌等人也聽其調遣。屈突通聞知李淵西行入關，親自率兵幾萬人趕赴長安，被劉文靜所阻。屈突通想去潼關向劉綱靠攏，王長諧搶先率兵襲擊並斬殺了劉綱，占據了都尉南城，屈突通不得不退守都尉北城，唐軍保住永豐倉，解除奪取關中後顧之憂，為順利占領長安打下基礎。李淵高興地說：「屈突通向西不能前進，向東沒有退路，只得觀望才能採取下一步行動，已經不必再顧慮他了。」于是命令李建成從永豐倉的駐軍挑選精兵，取道新封奔赴長樂離宮。

太子期間

李唐統一戰爭

攻入了長安。義寧二年（公元618年）春，李建成和李世民為正副統帥東征洛陽不克返回，夏，李淵在長安即位，立李建成為太子，裴寂為右僕射、知政事，劉文靜為納言。 李唐開始全面啟動統一方案：西線以李世民為元帥，由劉文靜、殷開山為副，繼續討伐薛舉；李建成與李淵為東西南北及長安幾條戰線做準備，積極整頓朝綱，調兵遣將，為宰制全國加緊籌備著，此事關全局性的戰略實施和物資保障，戰線如下：

南線：武德元年七月，李瑗安撫山南。 段綸任益州刺史，為關中提供穩定的後備物資。 四川在三國時期就已是富庶地區，意味關中及東線，物資充分保障。派鄭元壽領兵擊朱桀，派許紹、李靖、李孝恭對付蕭銑部隊。

北線：李淵遣李琛、鄭元壽賄賂突厥始畢可汗，穩住突厥，牽制突厥附屬勢力梁師道，派將經營北邊。

東線：李密兵敗降唐後，李淵派李神通安撫山東。李世民擊敗薛舉後，又派世民到東線戰場。派盛彥師鋤掉李密，籠絡李密謀臣魏徵，派魏徵安撫山東，還積極瓦解王世充部署，派人籠絡幽州羅藝部隊。

西線：聯合土谷渾討伐李軌，後派安修仁安撫平定李軌。

武德二年（公元619年），司竹盜賊祝山海作亂，自稱護鄉公，李建成率桑顯和前往將其平定。 四月，涼州人安興貴擒獲涼王李軌，率眾以河西諸郡向唐朝投降，李建成奉命前往原州接應。

武德三年（公元620年），劉武周被擊敗後逃往突厥，七月，李淵令李世民征討王世充，令李建成鎮守蒲州，防備突厥。

武德四年（公元621年），唐軍占領洛陽後，李建成派任瓌、盛彥師安撫河南。七月，劉黑闥起兵，劉黑闥為竇建德的部將，竇建德降唐後，由于李唐對降將沒有實行安撫政策，加上降將的疑懼心理，激起他們的反抗。劉黑闥很快複奪故地。李淵先後派李世民、李元吉徵討，雖取得了軍事上的勝利，但由于實行「懸民處死」的高壓政策，民心不穩，並沒有徹底解決問題。

武德五年（公元622年）六月，劉黑闥再次起兵，聲勢很大，再奪故地，李建成接受魏徵、王珪建議，請令征討。十一月初七（12月14日），李建成替代李元吉，成為討伐劉黑闥的唐軍主帥。經歷隋末戰亂，百姓渴望和平統一的社會環境，盼望國家安定。竇建德部將劉雅對勸他起兵的人說：「天下已安，樂在丘園為農夫耳。起兵之事，非所願也。」史載「時天下大定，其（高開道）將士多山東人，思還本土，人心頗離。」因此，李建成接受魏徵「今宜悉解其囚俘，慰諭遣之，則可以坐視離散」的建議，改變過去「妻子系虜，欲降無繇」的高壓政策，實行寬大安撫政策以爭取人心。史載：「建成至，獲俘皆撫遣之，百姓欣悅。」為了擴大影響，李建成讓被釋者互相轉告：「若妻子獲者，既已釋矣。」這一措施起到了爭取民心，瓦解鬥志的作用，起到了不戰而屈人之兵的效果。結果劉黑闥部隊「眾乃散，或縛其渠長降，遂擒黑闥。」十二月，李建成于魏州大獲全勝。

武德六年（公元623年）正月初五，劉黑闥逃到饒陽，被諸葛德威擒住，送到李建成面前。二月，李建成在洺州斬劉黑闥，平定山東。

李唐處死竇建德，激化了未附的山東豪傑，使山東部分力量對李唐缺乏信任，分化了山東豪傑對世民的支持。李世民在洛陽對部署及戰敗者的私下許諾不能兌現，弱化了世民的權威。平洛陽後，李建成、世民兄弟之間權力發生了碰撞，李世民有不服從調遣的傾向，威脅著太子建成的權威，開啟了兄弟權力之爭的序幕。

在李建成和李世民的政治鬥爭中，李建成不斷得到李淵的信任和支持，長時間都占據優勢，但是與其弟李世民的矛盾衝突日益加劇。早在武德二年（619年），李建成下屬李綱就在向唐高祖辭職時稱李建成「信讒慝、疏骨肉」，可見最早在那時，兄弟間隔閡已生。

唐突爭霸

李建成在秦王攻打王世充時，陳兵蒲城防備突厥的舉動。統一戰爭結束前，李建成多次巡防北邊防線，指揮所部主動出擊。

武德三年（公元620年）七月初一，李世民出兵討伐王世充。十三日，李建成到達蒲州駐屯，防禦突厥，並于廿五日指揮延州行軍總管段德操擊敗來犯的梁師都和突厥、稽胡聯軍。

武德四年（公元621年），稽胡酋帥劉仚成擁眾數萬作亂邊疆，正月廿三日李建成率軍征討，于鄜州與劉仚成軍交戰，大破劉仚成，斬首百餘級，俘虜一千多人。 李建成放走各稽胡首領幾十人，讓他們回到部落招降其他首領，劉仚成得知後與其他首領前來請降，李建成見這些部落民族兵馬太多，害怕他們再次作亂，準備將他們全部殺死，消息洩漏，劉仚成逃往梁師都那裡。李建成處死稽胡降兵六千餘人。 八月初二，李建成再次安撫北境。

武德五年（公元622年）八月十一日，李建成出豳州道，防禦突厥。

武德六年（公元623年）八月七月廿五日，李建成駐屯于北部邊境，防備突厥。

武德四年八月至武德五年十月，李建成一直局部打擊突厥，並初步部署了與突厥決戰的戰線。在東線戰爭掃尾工作中，李建成整編世民所部，領兵安撫山東劉黑闥部，巡幸幽州羅藝部隊，構建打擊突厥的戰線，處理一切有勾結突厥傾向的將領，淨化內部，為戰勝突厥做鋪墊工作。李淵與李建成還積極調整人事部署。

與李世民的鬥爭

楊文幹事件

根據《資治通鑑》《舊唐書隱太子建成傳》描述：武德七年（公元624年）六月初三，李淵帶著李世民和李元吉去銅川離宮仁智宮避暑，太子李建成監國，于京城留守。李建成趁勾結自己的死黨，原任太子東宮侍衛慶州都督楊文幹，讓楊文幹為自己招募驍勇，陰謀發動政變。並且命人送鎧甲給楊文幹。然而，負責送盔甲給楊文幹的爾朱煥和橋公山在極端的恐懼之下，主動向李淵報告了這件事情。李淵趕忙召李建成覲見。當高祖的使者到達時，太子舍人徐師謨勸李建成據城起兵，李建成沒有聽從，而是聽從詹事主簿趙弘智的意見，前往行宮請求皇帝寬恕，屏去官屬，直接入內叩頭請死，自投于地，不能起，幾乎喪命。高祖將其囚禁在帳內，以麥為其充飢，同時命宇文穎前往慶州宣召楊文幹。宇文穎至慶州以情告楊文幹後，六月二十四日，楊文幹發動兵變。李淵先派錢九隴、楊師道出兵鎮壓。六月二十六日，李淵向李世民許諾太子之位，以換取他平息叛亂。李世民出征後，李元吉與妃嬪為李建成求情，大臣封德彞固諫，李淵竟改變主意，令太子回京。七月初五日楊文幹為部下所殺，宇文穎被俘斬。李世民回來後，李淵隻字不提改立太子之事。最後，李淵將此事處理為「兄弟不能相容」，歸罪于東宮的王圭、韋挺 和秦王府的杜淹，將他們流放到雋州。李世民知道杜淹沒罪，送給他三百兩黃金。

此事件為太子謀反，處理結果卻是「兄弟不睦」；李世民本是帶兵平叛，卻遭到部下被流放的處罰。根據唐朝劉餗《隋唐嘉話》，裡面有「人妄告東宮」，司馬光在《資治通鑑》裡也引用了這句話。章太炎，李樹桐等學者認為：《通鑑》內有關楊文幹反事連李建成案的記載必與事實不符，所謂「楊文幹事件」是秦王府策劃的陰謀。

同年，唐高祖在城南打獵，李建成、李世民、李元吉都相從，高祖命三子馳射角勝。李建成將肥壯卻喜歡蹶的胡馬給李世民，李世民乘之，馬屢蹶，李世民卻總能及時跳到數步外，便對宇文士及說：「他想這麼殺我，但死生有命，怎麼能傷到我？」李建成得知後，就讓妃嬪進讒言，稱李世民自稱有天命為天下主。高祖大怒，先召李建成、李元吉，再召李世民指責，但正逢突厥入寇，高祖又改變態度與李世民商議對抗突厥。

但他卻在洛陽的軍政官員中建立了支持的基礎，以此來與李建成在長安的優勢相抗衡。武德八年（公元625年），李建成召李世民到東宮飲酒，李世民「心中暴痛，吐血數升」，被叔父淮安王李神通扶回西宮。李世民認為是李建成有心毒殺自己。唐高祖想派李世民去守衛洛陽，避免兄弟進一步衝突，但李建成和李元吉交換意見後認為這會使李世民在洛陽建立自己的勢力，提出反對，高祖也就沒有這麼做。

李建成招募兩千多名少壯人員來增強他在首都長安的力量，因駐紮在太子住地東宮內的長林門附近，稱長林兵。李建成長期在長安經營，與長安的官員和高祖許多妃嬪關係良好，尤其與高祖最寵愛的妃子尹德妃、張婕妤兩人關係密切，她們經常在高祖面前說李建成的好話：「至尊萬歲後，秦王得志，臣妾母子定無孑遺。」「東宮慈厚，必能養育臣妾母子。」等話，使李建成一直保持李淵對其的信任。

李元吉曾勸李建成趁李世民來齊王府時殺之，但李建成不想殺弟弟，阻止了。

玄武門之變

當大唐王朝開始漸漸穩定下來的時候，李建成一方和李世民為一方的早在戰爭時期已逐漸產生的隔閡，終于表面化且發展為你死我活的權力鬥爭。

根據兩唐書和《資治通鑑》的記載：李建成為了削弱來自李世民的威脅，作出了種種應對，李建成和李元吉一起，算計了李世民最重要的謀士房玄齡和杜如晦，將其開革，而後又派人行刺了李世民的重要將領尉遲恭，失敗後又詆毀尉遲恭，尉遲恭經李世民說情才免于一死。為削弱李世民力量，當突厥人于公元626年初入侵邊境時，李建成和李元吉去抗禦突厥人，並想要趁機帶走李世民幕府的精銳將領和士兵，李建成和李元吉還重金賄賂李世民手下的關鍵人物，希望他們倒戈相向，但尉遲恭、段志玄都拒絕了他們的拉攏。李世民對此展開了反擊，在軍方中立將領的默許中，做好了武裝政變的準備。為此李世民收買了玄武門的禁軍將領常何，使其聽命于己。

這時，李建成手下的率更令王晊又向李世民洩露李建成、李元吉意欲在昆明池殺害李世民的計劃，李世民遂在部屬建議下決意發動政變。武德九年（626年）六月三日，李世民向唐高祖告密李建成、李元吉與尹德妃、張婕妤通姦偷情，淫亂後宮。唐高祖立即對四人私通亂倫一事進行查驗。次日一早，張婕妤把李世民對他們的控告通知建成和李元吉，他們便決定不去朝廷而徑自去見皇帝說明詳情，因此打馬直奔太極宮，想為自己辯護，結果在玄武門遇到李世民的埋伏，李建成被李世民本人引弓射殺，終年37歲，李元吉也被尉遲恭射死，史稱玄武門之變。

李世民隨後掌握了宮中的禁軍部隊，唐高祖李淵無力回天，只得下詔以李世民主軍國事。事後，建成的兒子安陸王李承道、河東王李承德、武安王李承訓、汝南王李承明、巨鹿王李承義，李元吉的兒子梁郡王李承業、漁陽王李承鸞、普安王李承獎、江夏王李承裕、義陽王李承度等人都因而被殺，還在宗室的名冊上被刪除名字。李世民被立為太子，在其即帝位後，于十月初一丙辰日（626年10月26日）下詔，追封李建成為息王並以親王禮儀規格下葬，詔李建成東宮舊臣來會，于宜秋門哭之，謚隱。貞觀元年，唐太宗以宗室子李懷仁為李建成後嗣，後改以己子李福為李建成後嗣，貞觀十六年六月庚寅（7月8日）又追封為隱太子。

唐太宗入冥記

唐代小說，1900年發現于敦煌莫高窟藏經洞，原件藏于大英博物館。

太子府可考人員

• 太子太保杜伏威；

• 太子詹士、太子少保李綱；

• 太子左庶子、太子詹士裴矩；

• 太子詹士竇軌；

• 太子左庶子鄭善果；

• 太子中舍人、太子中允王珪；

• 隴西公友、太子中舍人、太子洗馬賀徳仁；

• 太子洗馬魏徵；

• 隴西公府諮議參軍、左元帥府錄事參軍、率更令蕭德言；

• 典膳監任璨；

• 太子中舍人殷聞禮；

• 太子舍人、太子中舍人李立言；

• 詹士府主簿、太子舍人趙弘智；

• 隴西公府記室、太子舍人庾抱；

• 太子舍人徐師謨；

• 太子通事舍人楊弘禮；

• 太子通事舍人張弼；

• 宮門大夫、太子家令韋慶嗣；

• 太子率更令盧赤松；

• 率更丞王眰；

• 太子監門率馬三寶；

• 東宮左率府錄事參軍張楚賢；

以上見《墓誌所見玄武門之變》作者：趙壯，南京大學。

• 太子率更令竇師幹；

• 太子左衛率裴龍虔；

• 屬官李安儼；

• 車騎將軍、武安縣公、副護軍薛萬徹；

• 翊衛車騎將軍馮立；

• 世子府諮議參軍、東宮中舍人王皂；

• 右衛率府鎧曹參軍唐臨；

• 宿衛楊文幹；

• 太子千牛李志安；

• 谷州刺史任瑰；

• 隴西公府祭酒、太子左衛驃騎、檢校左率韋挺；

• 太子左千牛、上大將軍李義余；

• 軍頭雷永吉；

• 左領軍長史陳演壽；

• 太子左千牛，右衛率府親府隊正王大禮；

• 太子右千牛、右率郎將徐慈政；

• 銀青光祿大夫、給事中、太子率更令歐陽詢；

• 太子學士陳子良；

• 司農卿、陽城縣公、開府儀同三司、農圃監韋雲起；

• 鴻臚寺卿韋慶儉；

• 太子家令、彭城郡公韋慶嗣；

• 益州道行台尚書郭行方；

• 太子中王知敬；

• 太子左衛率蘭謀；

• 長林軍可達志；

• 東宮左監門衛副率哥舒季通；

後世平反

在正史中，李建成和李元吉都被說得一無是處：李建成則無才無能，桀驁難馴，終日沉湎打獵酒色。李元吉則是暴虐無道，荒淫無度。這至少是這一時期，傳統史料對二人形象故意歪曲的部分結果。 司馬光曾指出當時的實錄對李建成和李元吉有偏頗不實之處。

《書唐隱太子建成傳後》

清末民初思想家、史學家、樸學大師章太炎在《書唐隱太子建成傳後》 指出：「史之失官，莫如書書唐隱太子與明建文事。建文紀年被革除，因不為著實錄，其時政令遂不可知，顧史官闕文而已。隱太子事，加誣乃已甚矣。按玄武門之訟，太宗率長孫無忌等伏兵門側，而隱太子無衷甲之衛，是太子無欲殺太宗心，借曰計慮不及，魏徵之智，豈後于房杜耶？不以伏兵教太子，是征亦未嘗勸之殺太宗也。凡太宗所表愬（音「訴」，誹謗意）于神堯者，與煬帝愬太子勇語絕相類，被鴆心痛，亦飾為之耳。又攻及隱昧，雲太子與宮嬪亂，誰見之誰証之？

太宗既立，懼于身後名，始以宰相監修國史，故《兩朝實錄》無信辭。吳兢劉昫不能為同異，雖宋子京亦不悟。唐人獨一劉餗明楊文幹事為誣告，而國史不採。司馬公頗欲闕疑，然不能盡汰也。夫以神堯素染胡俗，非滯于成周之制者，且又素幸太宗，過于塚子，令唐有天下之功皆在太宗，何憚而不更置耶？然卒立隱太子無所變者，以太子自有功。按倡議之謀，本裴寂、劉文靜啟之，太宗在側，故附成其說。隱太子不在側，故不得附成其說。太宗非有以過其兄也。其決策之大者，莫如師次賈胡，久雨乏糧，群議欲返太原，惟隱太子兄弟沮其計，使神堯仡然西進，終成大業。此其功亦二人兼之，觀溫大雅《創業起居注》所記，大郎二郎方略正等（溫大雅後亦為太宗所用，而《創業起居注》未嘗剟定，唐初信史，惟此一編今其書具存。）知太子非庸謹不可與立者，神堯所以卒無異志為此也。

其後削平東夏，實太宗之功為大，事乃在武德三年。後王魏勸太子親將討劉黑闥以立功，事雖卒就，比于太宗尚不逮，要創業時功非有異也。太宗以削平東夏自伐，故思奪宗。與煬帝以平陳自伐無異。奪宗之事，太宗與煬帝等。房杜為之謀主，與楊素等。凡事為耳目所習者，其取法也易，其慮之也亦深。神堯雖闇，獨懲于隋之高祖。訟者知其不決，則剚刃以先之，事乃有甚于煬帝者矣。蓋史者所以督視人君，唐初《兩朝實錄》，則房玄齡刪定以奏御者，其書玄武門之變，太宗且教令肆言之，是故論功則盡歸于此，舉惡則盡委于彼。此猶不置法司而令罪人躬自折獄。獄成矣，果足以欺百姓耶？雖然，有時直坐罪齊王而稱建成仁厚，此亦周內之不能盡也。」

《唐朝盛衰三百年：唐史十二講》

中國知名文史學家黃永年在《唐朝盛衰三百年：唐史十二講》 ：「建成、元吉也決非如歷史讀本中所詬罵是什麼「紈褲無賴子」、「兇險」之徒。《舊唐書》所說「建成殘忍，豈主鬯之才，元吉凶狂，有覆巢之跡，若非太宗逆取順守，積德累功，何以致三百年之延洪，二十帝之纂嗣？或堅持小節，必虧大猷，欲比秦二世、隋煬帝，亦不及矣。」好像由建成、元吉來做皇帝，唐政權就會馬上垮台，連秦二世、隋煬帝的結局都不如，也無非是受了《實錄》、《國史》對建成、元吉所加誣陷之詞的影響。

然而篡改歷史總是件心勞力拙的蠢事，今天仔細研讀文獻，仍不難看出建成、元吉對唐皇室的積極作用。李淵太原起兵後一直讓建成、世民共同充當統帥，直到正式稱帝為止，其間建成、世民都完成了任務，並無顯著的高下優劣之分。

至于政事上，建成當了太子後「高祖憂其不嫻政術，每令習政事，自非軍國大事，悉委決之」。也就是讓他學習主持日常工作。史書上也找不到他此時在政事上弄得如何糟的話，相反在這方面他起碼在經驗上要比李世民豐富得多。

（一）在出征問題上，前此建成以太子身份留長安練習政事，除武德二年出兵盩厔鎮壓司竹園的「群盜祝山海」，四年出兵鄜州擊破稽胡酋帥劉仚成的部落外，再未承擔軍事任務。而這兩次都是長安附近的小規模作戰，事罷即回長安，不能像李世民那樣培植私人軍事實力。元吉雖然出征山東，總還是李世民的副手，撈不到多少好處。現在趁李世民為李淵疏薄，他們趕快爭取出任大戰役的統帥。據《舊唐書·高祖紀》，武德五年（622）八月「突厥頡利寇雁門」，「遣皇太子及秦王討擊，大敗之」。十月「遣齊王元吉擊劉黑闥于洺州」。十一月「命皇太子率兵討劉黑闥」。十二月「皇太子破劉黑闥于魏州，斬之，山東平」。六年七月「突厥頡利寇朔州，遣皇太子及秦王屯并州以備之」。八年六月「突厥寇定州，命皇太子往幽州，秦王往并州，以備突厥」。最後九年「突厥犯邊，詔元吉率師拒之」，因玄武門之變而告吹。可見武德後期李世民已當不成大戰役的最高統帥，這個重要位置已逐步為建成、元吉取代。

（二）不僅公開取代統帥權，還用公開或秘密的手法來瓦解李世民已經結集的小集團勢力。用金帛招誘尉遲敬德、段志玄、李安遠等秦府將領，不成就加以排陷，曾下尉遲敬德于詔獄，要出程知節為康州刺史，連房玄齡、杜如晦這兩個大謀士都被斥逐出秦府。

（三）和李世民一樣大搞其結黨營私，擴充東宮、齊府的實力。李世民有以杜如晦、房玄齡為首的謀士和秦府文學館十八學士，建成有洗馬魏徵、中允王珪、左衛率韋挺等「盡心所事」的東宮官屬。

《唐史考辨》

台灣師範大學教授、隋唐史專家李樹桐在《唐史考辨》第九章「唐隱太子建成軍功考」中指出：「及太宗即位以後，必需要說出自己得即帝位的合理合法的根據來。于是造自己的功，造建成的過等等一套工作，是勢必要作的。在這個原則下，自然不能不去掩沒建成的軍功。 許敬宗奉太宗命作高祖實錄，掩沒建成的軍功一項工作，就在所修實錄里完成。掩沒建成軍功的方法有下列之多：

（一） 對建成立的軍功，除去建成之名。如平西河之役。

（二） 對建成部下將領立軍功的，不書明屬于建成部下。如克長安之役，將雷永吉改名為雷紹，而且不書明屬于建成部下。

（三） 對建成的職權或官銜從略，使受建成指揮的軍隊所建之功不屬于建成。如書「太子屯蒲州以備突厥」，及以後各戰役是。

（四） 對建成部屬的戰功，特別從略。如太子建成平劉黑闥時，他的部將錢九壟、竇琮等的軍功，毫不加描述。若與秦王世民平王世充、竇建德時對秦王及其部屬軍功的描述相比，尚不及數十或百分之一。

（五） 對建成的軍功或戰勝，往往改為戰敗或罪過。如霍縣之役。」

相關爭議

觀看《起居注》

「起居注」是史書的一種體式，史官依實記錄帝王每日言行，按年代順序編成。按規定，起居注是不准被記錄者本人看的，善行惡舉必記不漏。所以，其真實性不容質疑。按慣例，帝王大行之後，要依起居注修實錄，實錄既成，起居注即被銷毀，就是不毀亦因實錄的存世而起居注不再受重視。所以，唐以前的起居注早已不複存在，而唐代也僅此一種，彌足珍貴。

貞觀9年，李淵死後5個月，李世民第一次要求看《起居注》，未遂。

《貞觀政要》記載說：貞觀年間，褚遂良負責太宗《起居注》。李世民想取過來看，褚遂良以「不聞帝王躬自觀史」為由拒絕了。唐太宗說：「我有不好的言行，你也一定要記下嗎？」褚遂良說：「我的職責是記錄歷史，當然一定要記。」黃門侍郎劉洎：「即使褚遂良不記，天下人也記。」《舊唐書·褚遂良傳》和《資治通鑑》（第一百九十六卷）也載有此事。

次年，太宗再度要求看《起居注》 ，房玄齡等人就把國史加以刪減整理，撰寫成高祖和太宗的《實錄》各二十卷，當他看到「書六月四日事，語多微文」——史官對當年玄武門事變的內容含糊其辭，太宗告訴房玄齡：不必替他遮遮掩掩，反正玄武門事件本來就是像「周公誅管、蔡，季友鴆叔牙」那樣的義舉，目的是為了「安社稷、利萬民」，要求「削去浮詞，直書其事」。《資治通鑑》第一百九十七卷亦有記載。

這一行為給史學考究帶來極大困難，也遭到章太炎等學者的指責。之後學者在依據貞觀史料寫成的兩唐書和《資治通鑑》中，發現大量刪改史實的痕跡，這些史料往往自相矛盾、漏洞百出、不合常理。這些在黃永年《六至九世紀中國政治史》等文章書籍中都有揭露。王覺仁說，時至今日，關于貞觀君臣改史之事在學界幾乎已成定論，無可辯駁。認為這是由于李建成在玄武門之變被殺，李世民即位，史臣在編撰實錄和國史時，有意篡改了史實真相。

《大唐創業起居注》

作者溫大雅（572年－629年），字彥弘，太原人，曾任被李淵任命為大將軍府記室參軍，「專掌文翰」。 由于其長期置身中樞，又親歷了李唐王朝從醞釀到玉成的全過程，公餘修史，先後撰成《大丞相唐王官屬記》二卷、《今上王業記》六卷和《大唐創業起居注》三卷。《劍橋中國隋唐史》稱他為「唐朝建立的目擊者」。

《大唐創業起居注》記錄了大業十三年（617年）五月李淵太原起兵至武德元年（618年）李淵長安稱帝這段時間內發生的歷史事件，諸如李淵聯絡豪傑、醞釀起兵、南下滅隋、在長安立代王及被擁戴登基等。這段時間溫大雅做大將軍府記室參軍，所記多為親見親聞親歷。

《大唐創業起居注》約成書于高祖武德年間，涉及內容非常詳贍豐富，比之後來的《舊唐書》、《新唐書》、《資治通鑑》等史書，記言記事多有出入。摘其要者，如太原起兵的主謀是誰，李建成于滅隋過程的功業如何？以及李淵屈節突厥、李淵與李密的關係等，而《大唐創業起居注》似更貼近當時史實，這也是歷代治唐史者的共識。

太原起兵的謀劃

關于太原起兵的主謀，《舊唐書》、《新唐書》、《資治通鑑》等官修正史均歸功李世民，《新唐書·高祖本紀》說，大業十三年（617年）高祖做太原留守後，「世民陰與（裴）寂謀，寂因選晉陽宮人私侍高祖。高祖過寂飲酒，酒酣從容，寂具以大事告之，高祖大驚。寂曰：『正為宮人奉公，事發當誅，為此爾。』」後李淵被逼無奈：「吾兒誠有此謀，事已如此，當複奈何，正須從之耳。」司馬光在《資治通鑑》中說，「高祖所以有天下，皆太宗之功」。作為大唐帝國開國皇帝的李淵，在正史中，僅是個缺乏主見，任由李世民和其謀臣擺布的人，從太原起兵直至建國，幾乎沒起什麼作用。

而溫大雅的《大唐創業起居注》所記則完全不同，李淵不僅是太原起兵的主謀，而且為人英明、決斷、足智多謀，李世民僅起了協助作用。如同樣是大業十三年（617年）李淵被任命為太原留守，《大唐創業起居注》載：「帝（李淵）遂私竊喜甚，而謂第二子秦王等曰：『唐固吾國，太原即其地焉。今我來斯，是為天與。與而不取，禍將斯及。」此言謀隋而代之的雄心已暴露無遺了。若比較後代官修正史與《大唐創業起居注》，在李淵起兵滅隋這一過程中，由于溫大雅是按當時所見所聞所歷及時記載下來的，所以不像正史受後來的主流意識形態左右，應該說他的記載是最接近歷史真實的。

太子李建成與李世民的功業

在這個問題上，溫大雅作為秦王李世民的親信，在書中未免有誇大世民、貶抑李建成之處，但畢竟與正史受到太宗執政時期損益的史書截然不同，也被認為是相對客觀公正的記錄。由于李世民在玄武門之變中是靠殺兄逼父登上皇帝寶座的，而後世修史往往會替尊者諱。並且太宗「昔周公誅管、蔡而周室安，季友鴆叔牙而魯國寧。朕之所為，義同此類，蓋所以安社稷，利萬民耳。」已為玄武門定下基調。故在新、舊《唐書》及《資治通鑑》這樣的官修史書中，不僅要給李世民的奪位賦予正義的光環，還要對玄武門之變的受害者大加貶斥。如開創唐帝國的主角李淵庸庸無能，而太子李建成在滅隋興唐的風雲際會中更一無是處，或曰他的功績簿上一片空白。

但溫大雅在寫《大唐創業起居注》時，李世民還僅是秦王，與太子也未發生奪位之爭，因而溫大雅雖然與秦王關係殊近，卻不會也不敢厚此薄彼，只能秉筆直書。所以，在《大唐創業起居注》中，太子李建成隨父起兵爭戰，一路政績戰功卓著，而李世民並無殊勛。就在後世史家津津樂道的李世民苦諫父親勿從霍邑前線回師太原這件事上，《大唐創業起居注》也明確記錄，這是李建成與李世民共同的主張，而李淵也是欣然接受，並無「哭諫」一事。

關于兩唐書中所記載的李建成加害李世民等事情，由于政治鬥爭之殘酷，其有待詳查。

東宮毒酒事件的時間問題

新舊唐書李建成傳都差不多，安排在楊文幹事件之後。「後又與元吉謀行鴆毒，引太宗入宮夜宴，既而太宗心中暴痛，吐血數升，淮安王神通狼狽扶還西宮。高祖幸第問疾，因敕建成：『秦王素不能飲，更勿夜聚。』」

《資治通鑑》採用倒序手法，放在了武德九年六月一日條目下，正是玄武門事變前3天。《資治通鑑·卷第一百九十一·唐紀七》建成夜召世民，飲酒而鴆之，世民暴心痛，吐血數升，淮安王神通扶之還西宮。

《舊唐書·房玄齡傳》則把這一事件安排在建唐之前，而且沒有提到毒酒，只是中毒。接著就是房玄齡獻計誅殺兄弟逼退父親。「太宗嘗至隱太子所，食，中毒而歸，府中震駭，計無所出。」

人物評價

• 溫大雅：太子及王俱稟聖略，傾財賑施，卑身下士。逮乎鬻繒博徒，監門廝養，一技可稱，一藝可取，與之抗禮，未嘗雲倦。故得士庶之心，無不至者。

• 劉昫：建成殘忍，豈主鬯之才。有功曰祖，有德曰宗。建成、元吉，實為二凶。中外交構，人神不容。

• 司馬光：向使高祖有文王之明，隱太子有泰伯之賢，太宗有子臧之節。

• 王夫之：太原之起，雖由秦王，而建成分將以響長安，功雖不逮，固協謀而戮力與偕矣。

• 近代史學大家陳寅恪《唐代政治史述論稿》：然高祖起兵太原，李建成即與太宗各領一軍。及為太子，其所用官僚如王珪、魏徵之流即後來佐成貞觀之治的名臣，可知李建成亦為才智之人。

• 當代著名史學家黃永年在其中古史的力作《六至九世紀中國政治史》中指出：其實從第一手文獻《大唐創業起居注》來看，從太原起兵到高祖進入長安稱帝建唐，建成的功業並不亞于李世民；至于政事上，《舊唐書.建成傳》說建成當了皇太子後，「高祖憂其不嫻政書，每令習時事，自非軍國大務，悉委決之」，用今天的話來說，就是讓建成主持日常工作，學習做皇帝。而史書即使按太宗李世民定的調子多作改竄，也找不到建成此時在政事上弄得如何糟的話。相反，倒可以知道建成在這方面的經驗至少要比李世民豐富得多。」

• 史學者何木風：他是大唐第一位太子，也是被歷史扭曲了多年的真太子。

墓誌銘

李建成墓碑被盜多年，2013年出現于一起經公安機關破獲的盜墓案中，6月8日對外公布，全文如下：

::「大唐故息隱王墓誌。王諱建成。武德九年六月四日薨于京師。粵于貞觀二年歲次戊子正月已酉朔十三日辛酉。葬于雍州長安縣之高陽原。」

墓誌記載的高陽原為今西安市長安區郭杜鎮，具體出土地點約在郭杜鎮西北的羊村。墓誌上謚號「隱」字明顯為剜磨去原字後改刻。《唐會要》記載：

::貞觀二年三月（據志文當為正月），有司奏謚息王為戾。上令改謚。議，杜淹奏改為靈。又不許，乃謚曰隱。

知當時墓誌本已刻好，後依太宗旨意改字。挖去的字當為原來謚號「戾」字。

家庭

妻妾

• 原配某氏。

• 太子妃鄭觀音，繼室。生于隋開皇十九年（599年），隋朝大業十年（614年）嫁李建成。 鄭觀音比丈夫年輕十歲，成婚時李建成已虛歲二十六歲，且二人成婚時間比丈夫的弟弟李世民與弟媳長孫氏成婚時間更晚，推測鄭觀音並非李建成原配。卒于唐高宗上元三年（676年），年78。出自滎陽鄭氏，北魏太常卿，徐州刺史鄭道玉的曾孫女，北魏司徒府長史、諫議大夫、潁川郡太守、吳山郡公鄭諶的孫女，北齊本州大中正、吳山公、隋開府儀同三司、金紫光祿大夫、括州刺史鄭繼伯之女。早年史書中，關于李建成太子妃的記載僅「李安嚴（李安儼）與隱太子同取鄭氏」一句。

• 承徽楊舍娘，生于隋開皇十八年（598年），卒于唐高宗總章元年（668年），年71。出自弘農楊氏，北魏使持節大將軍、鄜豳燕成文扶鄧趙八州刺史、儻城郡公楊紹的曾孫女，使持節儀同大將軍楊長的孫女，隋通化府鷹揚郎將楊氏之女。武德初（618年）以良家子入宮，封承徽（良娣、良媛之後為承徽，從五品）。有女樂陵縣主，永徽中封，嫁洛州溫縣令于善詢。墓誌銘中有「望夫依石，思子臨台。」之句，可能有兒子死于玄武門之變。

子

李建成共有六子。除長子早卒，其餘五子都在玄武門之變被誅。

• 長子李承宗，620年六月封太原郡王，早卒

• 次子李承道，620年六月封安陸郡王，626年被誅

• 三子李承德，河東郡王，626年被誅

• 四子李承訓，武安郡王，626年被誅

• 五子李承明，汝南郡王，626年被誅

• 六子李承義，鉅鹿郡王，626年被誅

從李建成妻妾已出土的墓誌「東望吾子，西望吾夫」等語來看，李建成諸子很可能與李建成葬于一處。

女

至少有五個女兒

• 次女李婉順，嫁劉應道為妻，封聞喜縣主

• 五女歸德縣主，鄭觀音所生。鄭觀音墓誌有「巢傾穴毀，重承胎卵之仁。雖掌碎驪珠，而庭開虹玉，已絕倚閭之望，旋聞解瑱之歡。昔有陶嬰，恤孤資于紡績；緬惟梁寡，勵節在于衡泌」語，可能在玄武門之變後生下遺腹女，未詳與歸德縣主是否一人

• 樂陵縣主，楊舍娘所生，嫁洛州溫縣令于善詢。

備註

參考

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Background

Li Jiancheng was born in 589 during the reign of Emperor Wen of Sui. He was the oldest son of Li Yuan, then Duke of Tang, who was a hereditary noble, and Li Yuan's wife Duchess Dou, who was the daughter of Dou Yi (竇毅), the Duke of Shenwu and Northern Zhou's Princess Xiangyang. Duchess Dou would subsequently give birth to three of Li Jiancheng's younger brothers: Li Shimin, Li Xuanba (李玄霸, who died in 614), and Li Yuanji. She also gave birth to a girl child who eventually became Princess Pingyang, although it is not clear whether she was older or younger than Li Jiancheng. At some point, Li Jiancheng received the title of Heir Apparent of Tang.

Participation in Tangs founding

The rebellion against Sui rule

In 616, with rebellions beginning to engulf northern China and frequent Eastern Tujue incursions across the border, Emperor Yang of Sui commissioned Li Yuan to be the commander of Taiyuan, guarding it against both rebels and the Eastern Tujue. As the chief commander of Taiyuan, Li Yuan was obligated by law to leave his family behind. Li Jiancheng was therefore put in charge of the estate and became the head of the house of Hedong (河東, in modern Yuncheng, Shanxi) while Li Yuan was away. Li Yuan took his younger son Li Shimin with him to the city Jinyang, which was the administrative center of Taiyuan.

According to the traditional narrative in the official historical records, in 617 Li Yuan was persuaded by Li Shimin to rebel against Sui rule (see "Historical sources" below). Another source, Wen Daya (溫大雅)'s Da Tang Chuangye Qijuzhu (大唐創業起居注), attributes the decision to revolt to Li Yuan himself. When Li Yuan was initially assigned to Jinyang in 616, he was pleased and regarded his assignment as a divinely-granted opportunity. But just one year later, in 617, Li Yuan said to Li Shimin: "The Sui Empire is about to collapse and the next family to rule this country will be us. The only reason I haven't yet started a rebellion is because your brothers are still in Hedong". Li Yuan sent secret messengers to Hedong to transfer his family to Jinyang. During the journey one of Li Jiancheng's younger brothers, Li Zhiyun, died. He also summoned his son-in-law Chai Shao from Chang'an. At the urging of Li Yuan's daughter, Chai Shao left Chang'an on his own while she went into hiding.

Even before Li Jiancheng, Li Yuanji, and Chai Shao arrived at Jinyang, Li Yuan rebelled, declaring that he intended to support Emperor Yang's grandson Yang You, the Prince of Dai, as emperor, while honoring Emperor Yang as Taishang Huang (retired emperor). Yang You was nominally in charge of the capital city Chang'an at the time.

Li Yuan made both Li Jiancheng and Li Shimin key generals, and in nine days they captured Xihe Commandery (西河, roughly modern Lüliang, Shanxi), impressing their father. Subsequently, Li Yuan divided his forces into six armies, giving Li Jiancheng and Li Shimin command of three armies each. He also made Li Jiancheng the Duke of Longxi and Li Shimin the Duke of Dunhuang. Li Yuan then advanced toward Chang'an. As he approached Hedong, torrential rains prevented his army from advancing further. With rumors running rampant that Liu Wuzhou and the Eastern Tujue were about to attack Taiyuan, Li Yuan initially ordered a retreat back to Taiyuan. However, Li Jiancheng and Li Shimin argued that this would mean sure defeat, and Li Yuan changed his mind.

Li Jiancheng and Li Shimin then captured the fortress of Huoyi (霍邑, in modern Linfen, Shanxi), eventually convincing Li Yuan to bypass Hedong and directly advance toward Chang'an. After he crossed the Yellow River into Guanzhong (i.e., the Chang'an region), he sent Li Jiancheng with Liu Wenjing (劉文靜) east to guard Tong Pass and Yongfeng Storage (永豐倉) and to stop any potential Sui reinforcements from the eastern capital Luoyang. He also sent Li Shimin north of the Wei River to seize territory. Once Li Yuan himself approached Chang'an, he summoned both Li Jiancheng and Li Shimin to join him in a siege of Chang'an. In the winter of 617, Li Yuan captured Chang'an and declared Yang You emperor (as Emperor Gong). He was created Prince of Tang, and became the regent for Yang You.

In the spring of 618, Li Yuan sent Li Jiancheng and Li Shimin toward Luoyang, which was then under attack by the rebel leader Li Mi, Duke of Wei, ostensibly to help the Sui forces there. The Sui forces rejected the overture, and Li Jiancheng and Li Shimin returned to Chang'an.

Tang imperial reunification

Later in the spring of 618, Emperor Yang, then at Jiangdu (江都, in modern Yangzhou, Jiangsu), was killed in a coup led by the general Yuwen Huaji. When this news arrived at Chang'an, Li Yuan had Yang You yield the throne to him. He established the Tang Dynasty, and declared himself the Emperor Gaozu. He also made Li Jiancheng crown prince.

In 619, Li Yuan sent Li Jiancheng to attack the peasant rebel leader Zhu Shanhai (祝山海), the Duke of Huxiang. Li Jiancheng defeated Zhu. Later that year Li Gui, the Emperor of Liang, was captured in a coup by his official An Xinggui (安興貴), who then surrendered to Tang. Li Yuan sent Li Jiancheng to welcome An and to escort Li Gui to Chang'an, where An was executed by Li Yuan.

Meanwhile, Li Jiancheng was developing a reputation for leniency but was addicted to drinking and hunting. Li Yuan was worried that he was ignorant about politics and uninterested in working for the state. He added his key ministers Li Gang (李綱) and Zheng Shanguo (鄭善果) to Li Jiancheng's staff.

Campaigns against Tujue

On July 1, 620, Li Shimin was sent to fight Wang Shichong. In the fall of 620, reports came in that Li Zhongwen (李仲文), who was then in charge at Taiyuan, was planning to rebel. Li Yuan sent Li Jiancheng to Pufan (蒲反, i.e., Hedong) to guard against Li Zhongwen, while summoning Li Zhongwen back to the capital. Li Zhongwen complied and was later executed.

In spring 621 the Xiongnu chieftain Liu Xiancheng (劉仚成) harassed Tang's border territory. Li Yuan sent Li Jiancheng to attack Liu. Li Jiancheng captured a number of the Xiongnu and released their leaders. This led them to surrender in large numbers, and he then massacred them. Only Liu escaped and fled to Liang Shidu, the Emperor of Liang. In 622, Li Jiancheng was one of the commanders that Li Yuan sent, along with Li Shimin, Li Zihe (李子和), and Duan Decao (段德操), to counter an Eastern Tujue incursion.

Rivalry with Li Shimin

Meanwhile, an intense rivalry had developed between Li Jiancheng and Li Shimin, who now carried the title Prince of Qin. Although Li Jiancheng had made contributions towards Tang's reunification of China, Li Shimin had defeated a number of the most important contenders including Xue Rengao, the Emperor of Qin, Wang Shichong, the Emperor of Zheng, and Dou Jiande, the Prince of Xia. Li Shimin therefore had a stronger reputation in the army. Li Yuanji was also often relied on by Li Yuan as a general and had been created the Prince of Qi. He supported Li Jiancheng in his rivalry with Li Shimin, and often pushed Li Jiancheng toward a more hard-line position, wanting to be crown prince when Li Jiancheng became emperor. Li Jiancheng and Li Yuanji had better relations with Li Yuan's favored young concubines than Li Shimin did (their mother Duchess Dou had died before Tang's establishment), and those concubines helped rehabilitate Li Jiancheng's standing before Li Yuan. Li Yuan had considered making Li Shimin crown prince instead of Li Jiancheng, but his concubines persuaded him not to.

By winter 622, the only remaining major threat against Tang rule was Liu Heita, the Prince of Handong. He had been a Xia general, and rose against Tang after Li Yuan had executed Dou Jiande. He had been defeated by Li Shimin earlier in the year. Li Jiancheng's staff members Wang Gui and Wei Zheng argued to him that he needed some victories to establish his reputation, and Li Jiancheng volunteered to command the army against Liu Heita. Li Yuan sent Li Jiancheng to attack Liu, assisted by Li Yuanji. Around the turn of the year, Liu's forces were bogged down while attacking Tang's Wei Prefecture (魏州, in modern Handan, Hebei). Li Jiancheng and Li Yuanji engaged him at Guantao, crushing him. Liu fled north toward the Eastern Tujue, but was ambushed and captured by his own official Zhuge Dewei (諸葛德威), who delivered him to Li Jiancheng. Li Jiancheng executed Liu. China was by this point almost completely unified by Tang.

In 623, when the Eastern Tujue made another incursion into Tang territory, Li Yuan again sent Li Jiancheng and Li Shimin to guard against the attack. Meanwhile Li Yuanji suggested to Li Jiancheng that he could have Li Shimin assassinated when Li Shimin was visiting Li Yuanji's mansion, but Li Jiancheng refused, not having the heart to kill a brother.

In 624, Li Jiancheng requisitioned a number of soldiers from the general Li Yi, the Prince of Yan, to supplement his guard corps. This was against Li Yuan's regulations. Li Yuan rebuked Li Jiancheng when he found out, and exiled his guard commander Keda Zhi (可達志). Nevertheless, Li Jiancheng later requested the commandant at Qing Prefecture (慶州, in modern Qingyang, Gansu), Yang Wen'gan (楊文幹) to conscript troops, presumably to guard against Li Shimin. The officers Erzhu Huan (爾朱煥) and Qiao Gongshan (橋公山) informed Li Yuan that Li Jiancheng was encouraging Yang to start a rebellion so that they could seize power together. Li Yuan, then at Renzhi Palace (仁智宮, in modern Tongchuan, Shaanxi), was incensed, and summoned Li Jiancheng, then at Chang'an, to Renzhi Palace. Li Jiancheng briefly flirted with the idea of occupying Chang'an instead of accepting the order, but eventually reported to Renzhi Palace to request forgiveness. Li Yuan put him under arrest. When Yang heard this, Yang rebelled, and Li Yuan sent Li Shimin to attack Yang. Li Yuan promised Li Shimin that he would replace Li Jiancheng as crown prince, and that Li Jiancheng would be sent to the modern Sichuan region as the Prince of Shu. After Li Shimin left, however, Li Yuanji, Li Yuan's concubines, and the chancellor Feng Deyi, all spoke on Li Jiancheng's behalf, and Li Yuan changed his mind, released Li Jiancheng, and allowed him to return to Chang'an as crown prince. Li Yuan then blamed the discord between his sons on Li Jiancheng's staff members Wang Gui and Wei Ting (韋挺), and Li Shimin's staff member Du Yan, exiling them. Yang was subsequently assassinated by his own subordinates.

Later that year, Li Yuan, troubled by repeated Eastern Tujue incursions, seriously considered burning Chang'an to the ground and moving the capital to Fancheng, a suggestion that Li Jiancheng, Li Yuanji, and the chancellor Pei Ji agreed with. Li Shimin opposed the plan, however, and it was not carried out. Meanwhile, Li Shimin sent his confidants to Luoyang to build up personal control of the army there.

The Poisoned Wine at Eastern Palace

According to Zizhi Tongjian, on the first day of the 6th lunar month of 626, three days before the Xuanwu Gate incident, Li Jiancheng hosted a banquet for Li Shimin and Li Yuanji at his residence, the Eastern Palace. Li Shimin was carried back home after a night of drinking. Li Shimin reported through officials at his residence that he started vomiting a lot of blood after returning home. Li Yuan sent a royal decree to Li Jiancheng: "The prince of Qin (Li Shimin) has a low alcohol tolerance, therefore, he is forbidden to go out drinking at night." Li Shimin apparently interpreted the wine as an assassination attempt, but Li Yuan did not mention poison in his decree to Li Jiancheng. Li Yuan considered sending Li Shimin to guard Luoyang to prevent further conflict, but Li Jiancheng and Li Yuanji opposed the plan because they believed that this would give Li Shimin an opportunity to build up his personal power. They expressed their concerns to Li Yuan's ministers, who explained to him that this plan could escalate a brotherly rivalry into a civil conflict. Li Yuan therefore did not carry out the plan.

The date and the veracity of this event are both disputed. According to Zizhi Tongjian, it happened 3 days before the Xuanwu Gate incident. In Li Jiancheng's biography from the Old Book of Tang and the New Book of Tang, it took place after the Yang Wen'gan incident but several months before the Xuanwu Gate incident. However, in Fang Xuanling's biography from the Old Book of Tang, it happened before the founding of Tang, and wine was not mentioned. It remains a mystery whether or not someone attempted to poison Li Shimin at the Eastern Palace.

Death

By 626, Li Shimin was fearful that he would be killed by Li Jiancheng, and his staff members Fang Xuanling, Du Ruhui, and Zhangsun Wuji were encouraging Li Shimin to attack Li Jiancheng and Li Yuanji first. Similarly, Wei Zheng was encouraging Li Jiancheng to attack Li Shimin first. Li Jiancheng persuaded Li Yuan to remove Fang and Du, as well as Li Shimin's trusted guard officers Yuchi Gong and Cheng Zhijie (程知節), from Li Shimin's staff. Zhangsun, who remained on Li Shimin's staff, continued to try to persuade Li Shimin to attack first.

In summer 626, the Eastern Tujue were making another attack. Li Yuan was initially inclined to send Li Shimin to resist them, but at Li Jiancheng's suggestion sent Li Yuanji instead. Li Yuanji was given command of much of the army previously under Li Shimin's control. This further troubled Li Shimin, who believed that with the army in Li Yuanji's hands he would be unable to resist an attack. Li Shimin had Yuchi secretly summon Fang and Du back to his mansion, then sent an accusation to Li Yuan that Li Jiancheng and Li Yuanji were committing adultery with Li Yuan's concubines. Li Yuan responded by issuing summonses to Li Jiancheng and Li Yuanji for the next morning, convening the senior officials Pei Ji, Xiao Yu, and Chen Shuda to examine Li Shimin's accusations. As Li Jiancheng and Li Yuanji approached the central gate leading to Li Yuan's palace, Xuanwu Gate (玄武門), Li Shimin ambushed them. He personally fired the arrow that killed Li Jiancheng, and Yuchi killed Li Yuanji. Li Shimin's forces entered the palace and, under this intimidation, Li Yuan agreed to make Li Shimin crown prince. Two months later, Li Shimin succeeded to the throne. Li Jiancheng's five sons were all executed.

Li Jiancheng was initially reduced to commoner rank. After Emperor Taizong took the throne, he posthumously granted Li Jiancheng the title of Prince of Xi and assigned his own son Li Fu (李福) into Li Jiancheng's lineage as Li Jiancheng's heir. He also buried Li Jiancheng with the ceremonies due to an imperial prince. In 642, he restored Li Jiancheng's crown prince title. However, Li Jiancheng was never fully rehabilitated and his daughters still had the status of daughters of a common prince, rather than a crown prince.

Historical sources

Da Tang Chuangye Qijuzhu

"Qijuzhu" is a type of imperial diary which records the emperor's daily activities that appeared as early as the Han dynasty. The purpose of Qijuzhu is to help govern the emperor's behavior by faithfully recording the actions and words of the Emperor in court. The emperor must not read or ask about the Qijuzhu. In the Tang dynasty, imperial diarists were in charge of the Qijuzhu. According to convention, the Qijuzhu should be edited and the original diary destroyed after the death of the emperor.

The author of Da Tang Chuangye Qijuzhu (大唐创业起居注, "Imperial diary of the foundation of the Great Tang") was Wen Daya (c. 572 - 629 CE). He served as Li Yuan's staff of records and witnessed the establishment of Tang dynasty in 618. Da Tang Chuangye Qijuzhu was a three-chapter book with a detailed narrative and a firsthand account of the 357 days of insurrection. His work was finished before Li Shimin began censoring the official imperial records. Since Wen Daya was a supporter of Li Shimin, he did not feel a need to exaggerate Li Jiancheng's contribution to Tang's founding. As the only complete original court diary left from pre-Qing times, Da Tang Chuangye Qijuzhu is now generally considered a more reliable source on early Tang Dynasty..

Da Tang Chuangye Qijuzhu emphasizes that Li Yuan was the mastermind of the revolt against the Sui. Li Shimin, who was a teenager at the time, served only a secondary role in these events. In the official histories, Li Jiancheng was described as an incompetent crown prince. Wen Daya portrayed a different Li Jiancheng: a capable leader, generous and open-minded. He knew how to recruit talented people and did well in his early political career as a crown prince. Li Yuan, in Wen Daya's narrative, was a fearless leader with vision, courage and strategic planning.

Contemporary historians have re-examined the evidence for events contained in the official histories (the Old Book of Tang, the New Book of Tang and Zizhi Tongjian) and have concluded that important elements were probably fabricated during the reign of Li Shimin at his order. On the basis of other material, most importantly Da-Tang Chuangye Qijuzhu, historians have been able to correct some of the bias and distortions of the official histories about the founding of the Tang dynasty. Da Tang Chuangye Qijuzhu provides a clear example of how Li Shimin rewritten history for his own favor. It also explains Li Jiancheng's historical image contradictions in the official histories. The truth that had intentionally been distorted and ignored by later official historians can be found in the Da Tang Chuangye Qijuzhu.

Family

Spouse

• Princess Zheng Guanyin (599-676), married 614.

Sons

• Li Chengzong, Prince of Taiyuan (title granted in 620, died prematurely).

• Li Chengdao, Prince of Anlu (title granted in 620, executed and excluded from imperial clan 626).

• Li Chengde, Prince of Hedong (presumably born after 620, executed and excluded from imperial clan 626).

• Li Chengxun, Prince of Wu'an (presumably born after 620, executed and excluded from imperial clan 626).

• Li Chengming, Prince of Runan (presumably born after 620, executed and excluded from imperial clan 626).

• Li Chengyi, Prince of Julu (presumably born after 620, executed and excluded from imperial clan 626).

Daughters

• Li Wanshun (李婉順) (622-661), courtesy name Wāngniáng (尪娘), the second daughter, granted the title of Princess of Wénxǐ in 638, married Liú Yīngdào (劉應道).

• Princess of Guide, the fifth daughter.

Tombstone inscription

Li Jiancheng's tombstone was lost for many years. It was recovered in 2013, and the inscription was released to the public on June 8, 2013.

There are 55 words in total, as follows:

「大唐故息隐王墓誌。王讳建成。武德九年六月四日薨于京师。粤于贞观二年岁次戊子正月已酉朔十三日辛酉。葬于雍州长安县之高阳原。」

Modern Depictions

• Portrayed by Yan Yikuan in the 2005 TV series The Prince of Qin, Li Shimin.

• Portrayed by Choi Jung-woo in 2006-2007 SBS TV series Yeon Gaesomun.

• Portrayed by Qiao Zhenyu in the 2012 TV series Heroes of Sui and Tang Dynasties.

• Portrayed by Han Dong in the upcoming CCTV TV series Peace in Palace, Peace in Chang'An.