生平

早年生活

1497年（明應6年）3月14日，在鈴尾城（福原城，大江毛利一門福原麼俊居城，同時也是毛利元就的外祖父）元就出生，幼名松壽丸，當地現今留存了元就誕生的石碑。

1500年（明應9年），父親弘元因捲入大內氏及幕府之間的紛爭決定讓位給嫡男興元，松壽丸和弘元移居多治比猿掛城。

1501年（文龜元年），母親逝世。

1506年（永正3年），父親弘元因肝癌酒精中毒逝世，松壽丸（元就）自小在失去雙親下長大。及後松壽丸的居城被家臣井上元盛霸佔，因此松壽丸被戲稱為「乞食若殿」。由養母杉大方（弘元繼室）養大松壽丸。

1511年（永正8年），元服，名為元就。

1516年（永正13年），長兄興元因肝癌酒精中毒逝世，由興元的年幼的長男幸松丸就任。而附近的安藝武田氏看見毛利氏的混亂開始入侵毛利的領地，武田元繁率領大軍攻打吉川氏的有田城。吉川氏向毛利氏求援，元就為了挽救有田城，代替侄子幸松丸出兵救援，這是元就的初陣。他用計謀引誘武田氏先鋒熊谷元直追擊並墮入毛利氏的埋伏圈，熊谷元直全軍覆沒，後來總大將武田元繁欲來支援熊谷隊，兩軍在城外附近爆發混戰，最後武田軍總帥武田元繁被毛利軍弓箭手的箭矢射中而中箭陣亡（有田中井手之戰），此戰又被後世稱為西國桶狹間之戰。安藝武田氏隨之衰落。

1517年（（永正14年）），與吉川國經女兒妙玖結婚。

繼承家督

1523年（大永3年），元就支援尼子經久攻打安藝國中支持大內氏的藏田氏（藏田房信），是為鏡山城之戰，元就用計誘降敵將藏田直信開城進而攻陷鏡山城，因此威名大振，卻也讓尼子氏備感威脅，毛利幸松丸在此戰之後，以9歲幼齡病逝，最終家臣推舉元就為毛利家的繼承人。而反對他為繼承人包括了三位家老阪廣秀、桂廣澄、渡邊勝，在尼子氏的煽動下受到了其一門尼子豐久及重臣龜井秀綱的指示而試圖謀反，推舉元就之弟相合元綱取而代之。但元就在傅役志道廣良協助之下，取得了京都幕府足利將軍家的御內書，幕府將軍家認可元就是毛利家繼承人的書狀，清除了謀反勢力。元就的長男隆元誕生。

1525年（大永5年），由於敵對的尼子經久介入元就家督繼承人問題內耗下，種下元就『親大內，遠尼子』重要原因，元就決定轉而臣服於西邊的大內義興之下。

1529年（享祿2年），消滅曾經透過幸松丸介入毛利家的外戚石見國人眾高橋興光。同年與長年宿敵宍戶家修補關係。將長女毛利五龍嫁給宍戶氏家督宍戶元源嫡孫宍戶隆家。後來毛利家亦招攬了生城山天野氏及有著殺父之仇的原武田氏家臣熊谷氏，確保了安藝國盟主的地位。

1539年（天文8年），大內氏消滅了北九州大名少貳氏，大內氏與大友氏關係得以和解。因而安心地向安藝武田氏發動攻擊，首先是向佐東銀山城進軍，毛利元就跟隨戰鬥，城主武田信實逃離佐東銀山城，一度前往若狹國，後來成為了尼子氏家臣。

1540年（天文9年），尼子晴久率領三萬大軍入侵吉田郡山城，兵分兩路進攻毛利氏。先鋒由尼子氏精銳部隊新宮黨擔當，尼子國久為大將經備後進入安藝，毛利元就向姻親宍戶氏求援，宍戶氏及深瀨氏部隊在可愛川附近以投石戰術截擊新宮黨，尼子國久敗走。尼子晴久稍後親率尼子大軍經石見進入安藝，並得到毛利氏舊盟吉川氏加入，在吉田郡山城附近的風越山佈下本陣。毛利元就徵召全境領民加上原有的3000兵準備籠城戰死守，並向大內氏及附近安藝國人眾求援。基於劣勢，毛利軍採取游擊戰減少士兵傷亡，竹原小早川氏及駐扎在豐島的大內氏杉隆相部隊亦與毛利氏聯合抵抗，尼子勢亦把本陣轉移至青光山。戰事由8月初持續到11月底，他們終於等到大內氏援軍，在陶隆房率領1萬士兵支援下，毛利氏和大內氏部隊成功突襲尼子本陣，斬殺高尾久友，尼子氏戰況危急，原來反對尼子晴久出兵的尼子久幸不惜犧牲己命，掩護晴久撤退，結果被毛利氏中原善左衛門所殺。毛利和大內的襲擊成功迫使士氣低落的尼子軍撤退，毛利家確立了安藝國的勢力。同年，毛利軍順勢收復了被尼子軍攻佔的佐東銀山城，武田氏家督武田信實逃亡到出雲國，一門眾武田信重切腹自盡，安藝武田氏徹底滅亡。戰後元就將安藝武田氏旗下的川內警固眾加以組織化，後來成為了毛利水軍的基礎。

統一安藝與控制吉川、小早川

1543年（天文12年），與大內軍聯合攻打月山富田城（第一次月山富田城之戰），但是安藝國吉川氏家督吉川興經、出雲國人眾三澤氏、三刀屋氏等叛變，由於大內軍戰線過長，後路一度被尼子軍阻礙，毛利氏家臣渡邊通喬裝為元就的替身，與安藝國人眾小早川正平等人的拼死奮戰下，元就安全返回吉田郡山城。次年，毛利元就派遣兒玉就忠以及福原貞俊支援備後國三吉氏，但是支援軍被尼子軍所擊敗（布野崩）。

長期臣服于大內氏之下，亦為大內氏立下功勞的元就備受大內義隆的信任，大內義隆將大內氏家老重臣內藤興盛之女收為養女，並許配給曾在山口擔任人質的元就長子毛利隆元，以此強化大內和毛利的關係。

1546年（天文15年），正室妙玖病逝。毛利元就在召開軍議時，宣布退位隱居並讓家督由隆元繼承，然而讓出家督之位只是形式上，實權仍在元就手中。一來這是身為長子的隆元日後必須扛起毛利家的責任，讓他提早接觸政務有利無弊；二來恐怕就是元就打算退居幕後暗中使出計謀趁機統一安藝國。

1547年（天文16年），元就試圖控制正室妙玖出身的吉川氏，他利用當時吉川氏家臣團的不和，拉攏吉川興經叔父、妙玖的兄弟吉川經世，幫助經世剷除興經寵信的家臣大鹽右衛門尉，並與吉川經世、森脇祐有合謀迫使吉川興經隱居，將次男元春過繼吉川氏成為興經的養子，把興經送到毛利領內幽禁起來並監視。

1548年（天文17年），次男元春與妻子新莊局（熊谷信直之女）誕下嫡子鶴壽丸(即日後的吉川元長)。元就偕同三子，長男毛利隆元、次男吉川元春、三男小早川隆景同赴山口館拜見大內義隆，並定下了隆元與內藤興盛之女妙壽的婚事。

1549年（天文18年），大內義隆認妙壽為養女，嫁予長男隆元，是為尾崎局。

1550年（天文19年），三年後元就為免除後患，委派旗下的國人眾熊谷信直、天野隆重就將吉川興經及其子吉川千法師殺害。另外，元就亦介入安藝國人眾小早川氏的繼承人問題，當時小早川氏分為竹原小早川氏和沼田小早川氏，竹原小早川氏家督興景病亡無嗣，元就先把三子德壽丸送往竹原繼承竹原小早川氏，得到手島景繁及磯兼景通等竹原家家臣支持。沼田小早川氏家督小早川正平在月山富田城之戰陣亡，當時小早川正平長子小早川繁平雙目失明並不適合繼任家督，元就計劃讓隆景迎娶正平之女，並繼承沼田家，一統兩家小早川。為此元就重施故技拉攏沼田家家臣，如乃美宗勝、椋梨弘平、梨子羽宣平、國貞景氏，但也有部分小早川氏家臣反對，在親毛利派的沼田家臣協助下，反對派的田阪全慶、土倉秋平、近宗長平被殺，小早川氏落入毛利氏的控制下，小早川繁平隱居讓渡家督予德壽丸，兩小早川氏重新統一。透過這兩次事件毛利氏控制了吉川氏及小早川氏，確立了毛利兩川體制，吉川氏鄰近出雲國和石見國，小早川氏則握有水軍且位處安藝國東南，兩家直接併入毛利無疑大大增強毛利氏的實力。毛利元就透過婚姻外交結盟、軍事援助及過繼等手段，把毛利氏勢力逐漸伸展至整個安藝國，甚至接受大內氏的命令進入臨近的備後國，攻打親尼子氏的備後國人眾江田隆連、杉原理興等。

1550年（天文19年），毛利元就一舉翦除以家臣井上元兼為首的安藝井上氏一族，僅少數井上族人因或與毛利氏有姻親關係；或為元就之心腹而得以倖免，事件過後毛利氏家臣發表向毛利元就忠誠的宣誓文書。透過這次肅清行動，毛利元就加強家臣對主家的向心力，從此毛利氏正式轉化為戰國大名。

陶晴賢叛亂及嚴島之戰

1551年（天文20年），大內義隆被家臣陶晴賢推翻（大寧寺之變），大內義隆及嫡子龜童丸被弒，陶晴賢不欲負上謀反的罪名，因此向豐後國大友氏過繼大友晴英到大內氏，改名大內義長繼承大內氏以作傀儡。毛利元就一直對陶晴賢的謀反行動不置可否，待義隆死後元就先發制人，出兵攻擊平賀氏的頭崎城及大內氏的槌山城，元就出兵支援平賀氏宗家的平賀廣相奪回被大內義隆指派、來自小早川氏的平賀隆保所佔據的平賀氏家督位置，平賀隆保走投無路下自盡。然而毛利氏仍然未公開跟陶晴賢決裂，石見國吉見氏家督、大內義興女婿吉見正賴首先宣佈討伐陶晴賢，並聯絡元就共事。吉見正賴跟陶晴賢相比實力顯得懸殊，不久戰敗降服。可是這時候，毛利氏卻公開向陶晴賢斷交，並繼續攻打原屬大內氏控制的安藝國西部。

有鑑於兩軍的兵力動員差距，毛利軍最多隻能召集4000兵，而陶軍可以召集3萬兵。倘若毛利元就選擇正面跟陶晴賢作戰，可謂毫無勝算。毛利元就決定用計策對付陶晴賢。首先，毛利元就偽造一封書信，刻意洩露給陶晴賢知道，信中涉及毛利氏跟陶晴賢得力家臣江良房榮聯絡，並且得到江良房榮答應擔任內應。陶晴賢不虞有詐，當下捕殺了江良房榮。與此同時，毛利元就為避免和大內氏決戰之時受到尼子氏襲擊，毛利元就再次運用偽造書信的策略，同樣刻意把書信洩露給尼子氏家督尼子晴久，毛利元就假造與身兼尼子晴久叔父和丈人、精銳部隊新宮黨領導人尼子國久秘密交往，於是使晴久懷疑新宮黨忠誠，結果晴久召喚新宮黨到月山富田城覲見，以此成功誘殺新宮黨大部分核心成員，包括國久及其子誠久、敬久、誠久數子。誠久第四子在乳母保護下逃亡京都東福寺出家，他就是後來被山中幸盛擁立的尼子勝久。時為1554年，經過兩次精心策劃的反間計，元就成功削弱了大內氏和尼子氏。

為了開戰的準備，毛利元就仍需要多做些預備工作，他認為必須把陶晴賢引誘上安藝國南方的嚴島決戰，利用那裏不利於大部隊活動的地形，一舉消滅陶軍，於是他先在嚴島上建築宮尾城，委派己斐直之、新里宮內少輔率領少量士兵進駐，又派遣間諜進入大內氏領內散佈謠言，宣稱毛利元就害怕陶晴賢攻打宮尾城，讓陶晴賢信以為真。為了加強計謀的效果，元就指示擔任自己家臣、嚴島對岸的櫻尾城城主桂元澄寫信予陶晴賢以報父仇為名暗通陶晴賢，願擔任陶軍內應，配合其攻打嚴島云云。經過這幾件事，元就成功讓陶晴賢相信攻克宮尾城便能消滅毛利氏。

1554年（天文23年），陶晴賢派遣先鋒宮川房長先行出兵三千攻擊毛利氏，雙方在折敷畑山開戰，是為折敷畑之戰。宮川房長部隊和安藝國反毛利氏勢力合流，全軍增加到7000人，但卻被毛利元就、毛利隆元、吉川元春、小早川隆景四父子從三方包圍，宮川房長戰敗而亡，支持大內氏的安藝國人眾野間隆實被元就招降後滅族，至此安藝國完全落入毛利氏手中。

1555年（天文24年），陶晴賢不顧重臣弘中隆兼等反對決意親征嚴島，弘中隆兼等人主張應從陸路攻打毛利氏。陶晴賢得到屋代島水軍的援助，全軍分乘500艘船隻渡海攻打嚴島宮尾城。毛利元就在此時成功爭取到瀨戶內海海賊眾的三家村上水軍加入，據說當毛利元就求助村上水軍時，只要求村上水軍借出船隻一日時間搭載毛利士兵往嚴島。雙方主力在嚴島交戰（嚴島之戰），毛利元就、隆元和元春三父子乘著暴風雨登陸嚴島，並乘夜翻越博弈尾突襲駐扎在山坡下塔之岡的陶軍，另一方面小早川隆景及兒玉就方等率領毛利水軍和村上水軍包圍嚴島對開海面，並消滅大內氏的屋代島水軍三浦房清等，陸上的陶軍被毛利軍夜襲而一片混亂，潰不成軍。弘中隆兼及其子隆助嘗試組織士兵抵抗不果，雙雙陣亡。最終僅得4000士兵的毛利元就擊敗了5倍於己、號稱二萬大軍的陶晴賢，陶晴賢本人則一路奔逃到陶軍登陸地大元浦，他眼見海面盡是毛利水軍，自覺無路可逃便自盡了斷。經此一役，毛利氏加緊進攻大內氏領地，確立了橫跨周防、安藝兩國的霸權。

1555年（弘治元年），尼子晴久為奪取位於石見國的石見銀山，趁著大內家因陶晴賢弒主產生混亂，在聯合豪族小笠原長雄一舉攻奪了石見銀山。

1556年（弘治2年），同樣覬覦石見銀山的毛利元就也對石見伸手，策反尼子家山吹城守將刺賀長信，親自帶兵攻打護衛銀山的據點龜谷城。當時正發兵備前國的尼子晴久迅速轉向，發兵兩萬五千救援龜谷城，並在忍原與毛利軍分隊宍戶隆家的七千兵馬展開激戰，毛利軍在死傷數百後，宍戶隆家敗走，敗軍波及毛利元就和吉川元春的部隊，被尼子晴久伺機追殺擊潰。

1557年（弘治3年），出兵攻打大內氏（防長經略），接連擊敗或降服大內氏的國人眾，如杉隆泰、椙杜隆康、山崎興盛、江良賢宣等，包圍長門且山城，大內氏家老內藤隆世以毛利氏許諾保全大內義長性命為條件開城投降後切腹自盡，但毛利氏仍強逼義長自盡，大內氏宣告滅亡。

驅逐尼子氏及晚年

雖然毛利氏控制了大內氏大部份在中國地方的舊領土，毛利軍為奪取石見銀山屢屢向尼子家發起攻勢，1556年敗給尼子晴久後（忍原崩），1559年毛利元就再度進攻，雖拿下小笠原長雄鎮守的溫湯城，但無法打下山吹城，毛利軍在撤退時遭到山吹城守將本城常光的突襲受到重創，毛利軍大敗而回（降露阪之戰）。及後，毛利元就假意答應讓出石見銀山的管理權，方能讓本城常光倒戈投降，但本城一族隨即遭到毛利氏誅殺，銀山落入毛利氏手中。本城常光的死令不少一度轉投毛利氏的石見、出雲國人眾，如福屋隆兼、三澤為清、三刀屋久祐等重投尼子氏。

1561年（永祿3年）12月，尼子晴久病逝，由尼子義久繼任。尼子氏出現了混亂，幕府將軍足利義輝介入，雖然元就一度無意與幕府協調和解工作，但是為顧及面子，元就決定與尼子氏和睦，史稱雲藝和議。

1562年（永祿4年），毛利氏摒棄與尼子家和議的條約，尼子軍前線主將本城常光被毛利元就派人勸降。翌年派兵攻打尼子軍的白鹿城，毛利軍攻佔了白鹿城之後基本上將月山富田城包圍起來，對尼子氏來說白鹿城的失陷等於月山富田城已無屏障，大批國人眾被逼降服于毛利氏之下。其後為攻打月山富田城做好足夠的準備。

1563年（永祿5年），長男毛利隆元在備後國與當地國人眾和智誠春見面後突然急病逝世，對元就造成不少打擊，有傳隆元被下毒暗殺，元就命令和智誠春及隆元心腹赤川元保自盡以示負責。

1565年（永祿8年），毛利軍對月山富田城開始進行包圍，第一次包圍被尼子軍擊退。同年9月進行第二次包圍，期間成功散佈謠言云尼子氏家老宇山久兼已和毛利氏內通，義久盡信傳言，將負責處理兵糧的宇山久兼斬首處死。毛利軍經過長時間的包圍下，城內開始缺糧，城中開始以粥代飯，陸續出現投降的士兵。11月，尼子義久向毛利軍投降，與兩名弟弟移送安藝國監禁長達二十多年。當時毛利氏已經成為了控制八國的大名。

尼子家仍未正式滅亡，部份尼子家餘臣仍然嘗試作出反抗，山中幸盛推舉了尼子誠久在京都出家的兒子尼子勝久，試圖恢復尼子氏的政權，另外大友氏亦準備在九州進行爭奪原屬大內氏的豐前國和筑後國領地，長年流亡大友氏的大內義興之侄大內輝弘得到大友氏援助試圖恢復大內氏，向山口發動突襲，毛利陷入兩難情況。毛利氏為了進入北九州的門戶——豐前門司城多番和大友氏作戰，並且和古處山城的秋月種實結盟，又策反臣屬大友氏的立花山城城主立花鑑載和寳滿山城城主高橋鑑種，經過權衡得失之後，毛利元就決定與大友軍和解，撤兵返回中國地方平定大內氏和尼子氏的殘餘勢力。毛利放棄了九州的領土，把大友宗麟一直無法攻佔的門司城讓出，最後毛利軍擊敗了受大友氏援助入侵周防的大內輝弘。雖然多個出雲國的城堡被尼子軍攻佔，但毛利軍成功守住險要月山富田城。

1570年（元龜元年），毛利輝元率兵在布部山之戰擊敗了尼子軍，將尼子軍完全驅逐出雲。

在元就晚年期間，開始與京畿活躍的勢力接觸，幕府將軍足利義昭與織田信長關係決裂後，曾拉攏毛利元就參與信長包圍網，不過元就拒絕了義昭，元就並與信長維持良好關係，在元就逝世，織田信長派遣使者悼念他。

元就踏入晚年身體開始衰弱，曾經找足利義輝醫師曲直瀨道三治療，並且成功康復。最終1571年（元龜2年）6月14日在吉田郡山城病逝，死因可能是衰老或食道癌。

用兵方面毛利元就，根據各種文書的統計，其一生合戰次數超過200次，這在戰國時代是相當少見的。（當然也有說法把他的合戰次數壓縮到了48場，其中贏了43場，勝率依舊是最高的），且屢出奇計，經典戰例有：有田中井手之戰，此戰中敗殺了號稱今之項羽的武田元繁，以及吉田郡山城合戰，籠城軍不過千餘，配合大內義隆的援軍成功擊退了尼子晴久的數萬兵馬，還有嚴島之戰，借用村上武吉的水軍大破陶隆房二萬，斬首三千，被譽為中國的桶狹間（實際上應該是桶狹間合戰被稱為「本州的嚴島」）。其一生出奇謀無數，早年甚至有明朝人士朱良范在日本，曾為元就觀卜面相，稱讚元就說此人有唐宗宋祖之相，不可小覷。而元就的敗績也是很少的，日本人統計出來只有5場，而無論是5/48，還是5/200，這在日本戰國的失敗率都是相當小的。無疑可說毛利元就為日本第一常勝將軍，就算是武田信玄或上杉謙信，亦無法與之相較。

上杉謙信一生38戰23勝4敗11平，武田信玄一生54戰37勝8敗9平，整體質量無法跟元就相比。

三矢之訓和毛利兩川政治制度

三矢之訓原本見於毛利元就寫給其子的書信中，提到「三兄弟若不互相團結一致，將會像一支一支的箭被折斷；但若是團結起來將會成為三支綁在一綑的箭，就不容易被折斷了」的內容，書信中頗具警示的味道。後來被後人穿鑿附會，被描寫成現代人所知的以折箭教子的故事。簡而言之，現今的三矢之訓是虛構的，最明顯是在日本出現三矢之訓故事之前，中國已經有類似版本的教子故事，分別有吐谷渾阿柴教子的版本（南朝宋紀作阿柴，魏書作阿豺）和蒙古成吉思汗版本。

即便是如此，這個故事仍然深入民心，成為日本人公認的家教典範。

三矢之訓被視為成立「毛利兩川」制度的起點。所謂的「毛利兩川」制度是元就讓次子元春繼承山邊的吉川家和三子隆景繼承海邊的小早川家的家業，使之輔佐毛利宗家（毛利隆元的子孫）。這種制度在戰國時代並不罕見，更非毛利氏獨有。例如：北條氏相模的「相模之獅」北條氏康便把三子氏邦送往藤田氏、次子氏照送往大石氏，甚至把幼子氏秀送往越後上杉謙信處，圖謀繼承上杉氏；土佐的長宗我部國親把二子親貞送往土佐吉良氏、三子親泰送往香宗我部氏；還有東北陸奧的伊達氏更是政略婚姻同盟與周圍大名結成姻親。這些送子過繼他家成為戰國大名常用的手段，用以兼併其它家族的領地作為本家屏障，保障和增強自己本家的實力。

在這過程中，不但實質上控制了原屬其他家族的領土和經濟資源，還進一步使過繼子的家臣過渡為本家的直屬家臣，達到招攬人才的目的。

毛利兩川制度把靠近出雲的吉川氏配置為主管山陰道的軍事力量，接近瀨戶內海、擁有水軍的小早川氏主管山陽道的軍事力量。在這制度之下，毛利元就還重新分配家臣輔助兒子，如口羽通良、熊谷信直轉為吉川元春的重臣、井上春忠和清水宗治為小早川隆景的部下。毛利本家則居中，家督居城吉田郡山城及後來的廣島城仍然在安藝境內，受著吉川氏和小早川氏兩家的包圍受到保護。這種制度更平衡了吉川元春和小早川隆景的權力，兩人在評定會議的話語權完全平等，例如備中高松城之戰跟羽柴秀吉議和之後，吉川元春主張追擊撤退的羽柴軍，而小早川隆景則主張讓秀吉順利撤退靜觀其變，兩者的意見只待毛利家督毛利輝元定奪，而非吉川或小早川其中一者淩駕對方的意見，可見毛利元就生前定下這制度的要點正在於讓家族內部團結，避免互相猜忌，甚至自相殘殺。

百萬一心

「百萬一心」是毛利元就建築吉田郡山城所刻的石碑。唸法是「一日一力一心」，意思是國人同心合力有沒有什麼事辦不到成。據說這句話是為鞏固平民及豪族的心所想出來的，此外據說元就亦在戰爭曾經用過。此石碑在江戶時代被發現，現時為日語中的成語之一。

據說毛利元就非常重視家臣團的團結及對毛利主家的忠誠，曾經有一位家臣膝部中了毒箭，傷口化膿有斷腿之虞，毛利元就聽說後二話不說便俯下身來，吸啜家臣腿上傷口的毒液和膿水，再將之吐出。家臣因元就的行為而感動不已，當場淚流滿臉。此段亦為後世創作，原故事典型為戰國時代將軍吳起為士兵吸毒膿的故事，所謂謀將亦出自陰徳太平記、吉田物語等非史實創作，三折箭亦為中國故事日本版。

人物

• 與出雲的尼子經久和備前的宇喜多直家併稱中國三大謀將，為戰國時代中國地區擅用謀略成為戰國大名的代表人物。

• 鐵路唱歌（第二集山陽九州篇）其中一部份出自嚴島稱讚元就的歌詞。「毛利元就在此島，城外迎擊的敵人。將陶晴賢殺死，成為了武臣典範。」（）

• 有鑑於父親弘元及兄長興元因酗酒而早死，元就決定不喝酒，曾對嫡孫輝元以書信下達禁酒令。但是元就亦有試過將藥草混入酒中飲用。

• 雖是政略結婚，但與正室妙玖感情十分融洽，在妙玖過世後的私人書信中寫下了「最近一直思念著妙玖(近頃妙玖のことばかり思い出されてならない)」、「要是妙玖還活著的話...(妙玖が生きていれば・・・)」、「妻子從後頭治理著我這點還真是沒錯(內をば妻を以て治めというが本當にその通りだと思う)」等充滿思念的言語，元就在妙玖生前都沒有立側室，到了妙玖過世後兩年才開始迎娶側室。

• 元就曾經在毛利隆元死後，一度意志低沉。當他知道長男逝世後就暈倒，連續三天三夜哭泣不止。之後他曾說過：「想早點死，前往隆元的地方」。

• 對於版圖擴充非常謹慎，在他的遺言中，不要求他們統一天下。反而是讓子孫繼續領導家族，保住全日本六十國其中的五份之一。讓子孫繼續保持榮華富貴。

• 其中「三矢之誓」以及維持領地的遺言成為了黑澤明執導電影亂的藍本。

毛利元就的信仰及宗教政策

毛利元就的子女

官位、役職

• 1533年（天文2年）9月25日、從五位下。9月28日、右馬頭。

• 1560年（永祿3年）2月15日、從四位下、陸奧守。

• 1561年（永祿4年）12月8日、幕府相伴衆。

• 1562年（永祿5年）5月18日、從四位上、陸奧守。

• 1571年（元龜2年）6月14日、死去。享年75

• 1572年（元龜3年）、贈從三位。

• 1908年（明治41年）4月2日、追贈正一位。

毛利一門眾

• 內藤隆春（長男毛利隆元妻弟）

• 宍戶隆家（次女五龍局之夫）

• 熊谷信直（次男吉川元春岳父）

• 吉川經世（正室妙玖之兄）

• 市川經好（舅兄吉川經世之子）

毛利五奉行

• 國司元相

• 兒玉就忠

• 赤川元保

• 粟屋元親

• 桂元忠

毛利十八將

• 吉川元春

• 小早川隆景

• 宍戶隆家

• 熊谷信直

• 福原貞俊

• 粟屋元秀

• 飯田元親

• 志道廣良

• 口羽通良

• 國司元相

• 粟屋元親

• 兒玉就忠

• 桂元澄

• 赤川元保

• 天野隆重

• 渡邊長

• 吉見正頼

• 井上元兼

登場作品

;小說

• 毛利元就（東都書房、山岡莊八著）

• 元就和他的女人們（中央公論新社、著）

• 山霧：毛利元就之妻（文藝春秋、永井路子著）

• 霸道之鷲 毛利元就（新潮社、著）

• 智謀之人 毛利元就（中央公論新社、古川薰著）

• 毛利元就與戰國武將們（PHP研究所、古川薰著）

• 小說毛利元就（PHP研究所、著）

• 毛利元就：長於知略的西國霸者（PHP研究所、和田恭太郎著）

• 青雲之鷲（講談社、著）

• 毛利元就（、著）

• 毛利元就（、著）

• 毛利元就（東京文藝社、著）

• 毛利元就：令秀吉與家康畏怖的男人（、堺屋太一著）

• 元就軍紀（德間書店、著）

• 毛利元就與陶晴賢（、山本一成著）

• 荒天是吉日（、馬場誠二著）

• 我、並不窺望天下：毛利元就軍記（祥傳社、渡邊壽光著）

;影視劇

• 毛利元就（1983年、RCC、演：）

• （1993年、NTV、演：疋田泰盛）

• 毛利元就（1997年、NHK大河劇、演：）

;遊戲

• 戰國無雙系列（光榮公司，石川英郎配音）

• 毛利元就傳（光榮公司）

• 戰國Basara系列（Capcom，中原茂配音）

• 戰國蘭斯

• 美男戰國～穿越時空之戀，配音：小西克幸

解釋和腳註

參考書目

• 石黑吉次郎『安西軍策 毛利元就合戰記（日本合戰騒動叢書）』（勉誠出版） ISBN 978-4-585-05111-4

• 小和田哲男『戰國武將「名將」のすごい手の內』（三笠書房） ISBN 978-4-8379-7656-1

• 『曆史群像1996年12月號 総力特集〜毛利元就軍団』（學研）

• 金谷俊則『毛利隆元』（中央公論事業出版） ISBN 4-89514-301-5

Early life

Mōri Motonari was born on April 16, 1497, under the childhood name Shōjumaru (松寿丸) in a small domain of Aki Province. He was the second son of his father, Mōri Hiromoto. His mother was a daughter of Fukubara Hirotoshi (福原広俊), but her name is unknown. His birthplace is said to be Suzuo Castle (鈴尾城), the base of the Fukubara clan and his mother's home. Today, there are stone monuments at the ruins of Suzuo Castle to commemorate the birthplace of Motonari at the castle.

In 1500, his father was involved in a power dispute with the Ashikaga shogunate and the Ōuchi clan and decided to retire. He handed over the head position of the clan to his eldest son, Mōri Okimoto and moved to Tajihi-Sarugake Castle (多治比猿掛城) with his son Shōjumaru. Okimoto then took over Yoshida-Kōriyama Castle, the main stronghold of the clan.

History remembers the young Mōri Shōjumaru as a fearless daredevil. It is said he escaped by night with some other children from his father's castle and met lord Amago Tsunehisa and his troops. Shōjumaru thought they were the ghosts of the Heike clan samurai, and so tried to become famous with a ghost hunt, a practice favored for the education of the youth of buke families. And so, Shōjumaru came openly to challenge the mounted warrior who looked to him like the general of the troops. It was Tsunehisa. The other children were trembling in fear, but not Shōjumaru. The young lord shot an arrow at the veteran lord. Tsunehisa swiftly caught it with his bare hand. Impressed by the bravery of his young opponent, Tsunehisa spared the boys, looking forward to battle against an adult Motonari.

The following year in 1501 his mother died and in 1506 his father died due to alcohol poisoning. Shōjumaru stayed at Tajihi-Sarugake Castle but his vassal Inoue Motomori (井上元盛) began embezzling land and was turned out of the castle. Because he was now both impoverished and from a powerful family he was called the "Beggar Prince" (乞食若殿) by the common people. The young Shōjumaru was raised by a foster mother Sugi no Ōkata (杉大方), who was a great influence on him; they grew very close. She got him in the habit facing the sun and saying a Buddhist prayer every morning.

In 1511, Shōjumaru officially became an adult and had his genpuku ceremony. He received the name Mōri Motonari (毛利元就).

In 1516, his brother Okimoto died suddenly like their father due to alcohol poisoning. Okimoto's infant son, Kōmatsumaru (幸松丸) succeeded as head of the clan and Motonari became his regent.

After the sudden deaths of his father and brother the Mōri clan was left weak and vulnerable. The most powerful lord of the region, Takeda Motoshige (武田元繁) of Sataukanayama Castle (佐東銀山城), took advantage of the situation and gathered an army of 5,000 and in October, 1517 advanced into the territory of the Mōri's Kikkawa clan allies surrounding Arita Castle (有田城). A few weeks later, Motoshige dispatched a raid into the Mōri clan's territory and set fire to houses in Tajihi (多治比). Motonari went in place of his nephew Kōmatsumaru to relieve Arita Castle from the advancing Takeda forces. This was Motonari's first battle that would decide the fate of the Mōri clan and would become known as the Battle of Arita-Nakaide.

Battle of Arita-Nakaide

With most of the Ōuchi clan forces preoccupied in Kyoto with Ōuchi Yoshioki, the Mōri were unable to call on them for assistance, and Motonari instead mobilized his clan and called on their supporters. Motonari was also aided by his younger brother, Aiō Mototsuna. In total the Mōri strength comprised around 850 men, reinforced by 300 from the Kikkawa clan, for a total of around 1,000. This force marched towards Arita Castle and on the way encountered the Takeda vanguard, commanded by Kumagai Motonao (熊谷元直), commanding about 500 men. The Mōri and their allies stood off and engaged the Takeda with archery fire. Kumagai Motonao was in the front ranks and was encouraging his men when he was struck and killed by an arrow. Takeda Motoshige was meanwhile with the main army at Arita Castle. Learning of Motonao's demise, he drew up his forces and marched to engage the smaller Mōri resistance. The Takeda encountered the Mōri and Kikkawa occupying the opposite bank of the Uchikawa River (又打川) and a bitter struggle ensued. Heavily outnumbered, the Mōri-led forces began to falter and fall back, rallying only when Motonari pleaded with them to stand their ground. Takeda Motoshige himself advanced across the river on horseback but was struck by an arrow and killed. The Takeda broke and retreated, leaving Mōri Motonari the victor. The battle was the start of the decline of the Aki-Takeda clan and the start of the military expansion of the Mōri. Mōri Motonari's name finally became known in the country.

Service under Amago clan

In 1518 Amago Tsunehisa made a series of raids into the Ōuchi clan's lands, falling back with the return of Ōuchi Yoshioki from Kyōto. In 1521 a formal peace treaty was signed between the two clans but it lasted but one year. Also sometime around 1522, Motonari married the daughter of Kikkawa Kunitsune (吉川国経) the lord of Ogurayama Castle; this match would not only secure the friendship of the Kikkawa clan but would in time produce three fine sons. This was an important alliance as the Kikkawa were powerful in Aki Province and their land lay directly to the north of Yoshida, the Mōri heartland on the border with Iwami Province. Motonari had thus already extended his influence north in the direction of the silver-rich Iwami Ginzan Silver Mine and south towards the Inland Sea.

In 1522, Tsunehisa marched into Aki Province, forcing Motonari, whose lands sat directly in the Amago's path, to submit. Motonari was immediately dispatched against Kagamiyama Castle (鏡山城) while Tsunehisa himself struck at Kanayama Castle (金山城). Tsunehisa made no progress against Kanayama and retreated, but Motonari was eventually successful at the Battle of Kagamiyama Castle (鏡山城の戦) in 1523. Motonari had problems taking the castle because the lord of Kagamiyama Castle, Kurata Fusanobu (蔵田房信), put up a strong fight, so Motonari persuaded his uncle Kurata Naonobu (蔵田直信) to betray the castle. After the battle Motonari tried to save Naonobu but Amago Tsunehisa executed him for his shameful and disloyal act. It may be that Tsunehisa became aware of Motonari's talent and wary of his expansion, for from then on a rift would grow between Tsunehisa and Motonari.

Early Rise

Leadership of the Mōri clan

In July 1523, Motonari's nephew Kōmatsumaru, the titular head of the clan, died suddenly at the age of nine. The senior Mōri vassals met and decided to offer the leadership to Motonari and on August 10 he entered Yoshida-Kōriyama Castle as its new lord. However, some among the senior vassals dissented from the decision and in 1524 any sense of security was broken when Mōri suffered the defection of his vassal Katsura Hirozumi (桂広澄), and was forced to defeat the traitor in open battle not far from Yoshida-Kōriyama Castle. Also in 1524, Motonari learned of a conspiracy led by a vassal, Sakagami Sosuke, to murder him and elevate his half-brother Aiō Mototsuna to the leadership. The rebellion was crushed at Funayama Castle in April.

Service under Ōuchi clan

Along with the family troubles concerning succession, Motonari and Amago Tsunehisa gradually grew hostile towards one another. In March, 1525 Motonari and several other local lords decided to change allegiance to Ōuchi Yoshioki. In June, Yoshioki sent his army to Kagamiyama Castle and took it from the Amago clan. Considering Kagamiyama's weak defenses on a low hill, Yoshioki built a new castle called Tsuchiyama Castle at the western edge of Saijo Basin on a high mountain and demolished Kagamiyama.

In 1529 Yoshioki died and was succeeded by his son Ōuchi Yoshitaka. Amago Tsunehisa began negotiating with Takahashi Okimitsu (高橋興光), a maternal relative of the late Mōri Kōmatsumaru who had earlier schemed to place Motonari's brother, Aiō Mototsuna, as head of the Mōri clan. Motonari acted quickly and crushed the Takahashi clan, taking their vast territory from Aki Province to Iwami Province. He paid a high price for the conquest, however, because Motonari's eldest daughter had been a political hostage of the Takahashi clan and was murdered by them in revenge.

A rebellion broke out against the Ōuchi clan in 1532; in response, thirty-two vassals presented Motonari with an oath in which they sought a guarantee that he would not require them to give up their status as small-scale lords, in return for which they promised to jointly undertake the repair of walls and irrigation ditches and the disciplining of traitorous vassals.

On September 25, 1533, Motonari was granted the imperial court rank of the Junior Fifth, Lower Grade in remembrance of his ancestor Ōe no Hiromoto's title. Ōuchi Yoshitaka approved of this and paid the stipend for the position. Although this place at court had become only a sinecure, Motonari nevertheless demonstrated to the other lords in Aki Province that he had the backing of both the imperial court and the Ōuchi clan.

Consolidation of Mōris holdings

In 1534, Motonari began consolidating the Mōri's holdings in Aki, gathering local allies, chief among these being the Shishido, Kumagai, and Amano. He also married one of his daughters to Shishido Takaie (宍戸隆家).

In 1535, Tagayama Castle (多賀山城) surrendered to Motonari. Over the next twelve months Motonari defeated the Miya and Tagayama clans. Motonari also made ties with his former enemies, the Aki-Takeda clan and Kumagai clan, creating a strong network of power. By the end of the decade the Ōuchi and Amago families began to see the Mōri with new respect and suspicion. The Amago clearly would not have any faith in Motonari as he had betrayed them and defeated their allies. The Ōuchi were also growing suspicious of the Mōri's growing power, so in 1537, Motonari's eldest son Mōri Takamoto was given as a political hostage to the Ōuchi clan to strengthen their relationship. He would stay until 1540.

In 1539 Ōuchi Yoshitaka fought the Ōtomo clan and Shōni clan of northern Kyūshū, defeating the Shōni clan to win control of the area. In the same year, Sato-Kanayama Castle (佐東銀山城) owned by the Takeda clan on the Amago side fell to the Ōuchi clan despite reinforcements from the Amago clan. The family head Takeda Nobuzane (武田信実) escaped to Wakasa (若狭) where the Takeda had a branch family and later took refuge with the Amago clan.

Siege of Koriyama

Amago Tsunehisa had nominally retired and turned over the leadership of the clan to his grandson, Haruhisa (also known as Akihisa). Amago Haruhisa conceived of a plan to destroy Mōri Motonari and bring Aki province under the sway of the Amago. When a council of the Amago retainers was called to discuss the planned campaign, almost all spoke in favor of the attack. Amago Hisayuki, however, considered the risks to be too great and spoke out against it, but was derided by Amago Tsunehisa as a coward and publicly humiliated. Amago Hisayuki was given the task of harrying the Mōri's ally, the Shishido clan in Aki, as part of an initial and concurrent operation of the larger Amago campaign into Aki. Amago Haruhisa, with 30,000 men, attacked Motonari's main base, Yoshida-Kōriyama Castle, which was defended by 8,000 men.

The initial phase of the campaign began in June 1540. Amago Hisayuki, his son Amago Masahisa and his nephew Kunihisa led their troops to attack the domain of Motonari's ally, the Shishido clan. This foray had little effect except to deny Haruhisa of some of his most capable generals and soldiers for the attack on Yoshida-Kōriyama Castle.

In August, Amago Haruhisa gathered a force of 30,000 and departed Izumo Province, moving into the vicinity of Motonari's Yoshida-Kōriyama Castle and establishing a headquarters nearby. Meanwhile, Motonari had evacuated over 5,000 of Yoshida's citizens inside the walls of Yoshida-Kōriyama Castle, which was defended by around 3,000 soldiers. By this time urgent requests for aid had been dispatched to the Ōuchi in Suo Province. Two days after arriving, the Amago launched an attack on Yoshida-Kōriyama Castle, which continued for several months.

The Ōuchi relief army, consisting of 10,000 men led by Sue Takafusa, finally departed Suō Province in November, pausing on Miyajima to offer prayers for victory at the Itskushima Shrine before landing in Aki and marching towards Yoshida-Kōriyama Castle. They arrived outside Yoshida-Kōriyama Castle in December 1540, four months after the siege had begun. A series of skirmishes ensued between the opposing armies into the following month (January, 1541), which was largely to the detriment of the Amago. Motonari successfully defended his castle from an attack by Amago Haruhisa in the 1540–41 Siege of Koriyama.

In the meantime, the other Amago force under Amago Hisayuki that had been dispatched to threaten the Shishido arrived. Its headquarters on Tenjinyama (天神山) were attacked by the Mōri and Ōuchi. In the ensuing action Amago Hisayuki was killed by an arrow and the Amago suffered heavy losses. In the wake of this fight, the Amago retainers, noting the army's dwindling supplies and poor morale, elected to retreat. The Mōri and Ōuchi duly pursued but were hindered by snow.

The same year (1540), they attacked the Amago retainer Takeda Nobuzane (武田信実) who had been hiding with the Amago clan at Sato-Ginzan Castle. Nobuzane fled to Izumo Province and the Aki-Takeda clan was utterly annihilated. In addition, Motonari took over the Kawachi Keigoshu (川内警固衆), a pirate organization owned by the Aki-Takeda clan, which would become a large part of the Mōri navy later.

First Siege of Toda castle

From 1542 to 1543 Motonari followed Ōuchi Yoshitaka in the First Siege of Toda Castle. In this battle they penetrated deep into the Amago clan territory but their supply line was broken and Kikkawa Okitsune (吉川興経) betrayed them. Motonari surrounded Gassantoda Castle (富田城) but the Ōuchi troops retreated. During the retreat Motonari almost lost his life but his general Watanabe Hajime covered Motonari's escape with a heroic rearguard action. Motonari returned safely to Aki Province. As a result of the battle the power of the Ōuchi clan weakened.

Extended Mōri clan power

In 1544 Motonari gave his third son, Tokujumaru (徳寿丸), for adoption to the Numata branch of the Kobayakawa clan (沼田小早川氏) who were famous for their naval forces. Tokujumaru later became known as Kobayakawa Takakage. This same year Amago Haruhisa's expeditionary force attacked the Miyoshi clan in Bingo Province. Motonari dispatched generals Kodama Naritada and Fukubara Sadatoshi against Haruhisa but they were forced to retreat.

Motonari lost his wife Myōkyū in 1545 and, crying, he did not emerge from his room for three days.

Motonari then announced that he intended to enter retirement in 1546 and hand over the leadership of the Mōri to his son Mōri Takamoto. However, it was understood by all that Motonari was still the true head of the clan wielding all the power.

In 1547 Motonari sent his second son, Shōnojirō (少輔次郎), to be adopted by the Kikkawa clan which was his deceased wife Myōkyū's family. Shōnojirō would become known as Kikkawa Motoharu. The head of the clan, Kikkawa Okitsune (吉川興経), was a rival of Motonari who had allied himself with the Amago clan in the 1540s. Motonari responded by pressuring Okitsune to adopt his son Motoharu and in 1550 Okitsune was compelled to retire, later being killed on Motonari's orders by Kumagai Nobunao (熊谷信直). Kikkawa Tsuneyo (吉川経世), who was the uncle of Okitsune stayed on as a retainer of the Mōri. In 1550 Motoharu entered the Kikkawa clan's main castle as its lord.

Motonari also intervened in the succession of the Kobayakawa clan. His son, Kobayakawa Takakage was already head of one branch of the clan, the Numata. The other branch, the Takehara, had lost their clan head Kobayakawa Masahira (小早川正平) at the Siege of Toda Castle and the new head of the clan, Kobayakawa Shigehira (小早川繁平) was young and blind from an eye illness. In 1550, with the backing of Motonari, Takakage also became head of the Takehara branch, merging the two branches of the clan. With this action the armed retainers of both branches became Motonari's to command.

In 1549 Motonari went down to Yamaguchi with his sons Motoharu and Takakage. Ōuchi Yoshitaka's vassals Sagara Taketō and Sue Takafusa were engaged in a dispute over the future of the Ōuchi clan. After his defeat at the Siege of Toda Castle, Ōuchi Yoshitaka had grown tired of fighting battles and had retreated to work with literature and the arts. Motonari was sick during his stay in Yamaguchi and it took him three months to return to Yoshida-Kōriyama Castle. His caretaker while he was sick was Inoue Mitsutoshi (井上光俊).

Inoue Motokane (井上元兼) was the son of Inoue Mitsukane (井上光兼) and the de facto head of a notable Aki family that nominally served the Mōri clan. He held Tenjinyama (天神山), which was just to the south of Motonari's Yoshida-Kōriyama Castle. As Motokane grew more powerful militarily and economically, he began to test the leadership of Motonari, who he became openly critical of. In 1550 Motonari forced Motokane and many members of his household to commit suicide on the grounds of treasonous behavior, an act that secured the Mōri as Aki's most powerful family. The Inoue family were afterwards allowed to continue on as Mōri retainers. Motonari's previous caretaker in Yamaguchi, Inoue Mitsutoshi, escaped the purge.

At this point Motonari now had Iwami Province with the Kikkawa clan, Bingo Province, Seto Inland Sea with the Kobayakawa clan and with the two forces nearly dominated the whole of Aki Province.

Conflict with Ouchi

Tainei-ji incident

In 1551, Sue Takafusa revolted against his lord Ōuchi Yoshitaka in the Tainei-ji incident, forcing him to commit seppuku. Takafusa changed his name to Harukata on this occasion and installed the next lord of the clan, Ōuchi Yoshinaga, but effectively led the Ōuchi clan and its armies, intent on military expansion. In 1554, Mōri Motonari became the leader of the Mōri clan. As a vassal of the Ōuchi clan, he wanted to avenge the betrayed Yoshitaka, and so he rebelled against Sue, whose territorial ambitions were depleting clan resources.

The Sue gathered a large army of as many as 30,000 men. Motonari, while stronger than ever, could scarcely muster half that. Nonetheless, he fared well in the early stages of their conflict, defeating Sue troops at the Battle of Oshikibata in June. By using what had already become hallmark Mōri trickery and by bribing a number of Sue's men, Motonari managed to balance out the odds somewhat. For his part, Sue made no major moves against Koriyama, and with the end of the year's campaigning season, Motonari was allowed some breathing space.

Battle of Miyajima

In the early summer of 1555, Sue was again threatening, and Motonari was hard-pressed. Harukata was by no means a poor fighter, and the danger of Motonari's retainers and allies deserting the Mōri led him to adopt a bold and unorthodox scheme. His plan involved Miyajima, home to the Itsukushima Shrine and a place combatants had traditionally avoided on religious grounds. Mōri's generals had suggested the occupation of Miyajima, which was strategically located just off the Aki coast in the Inland Sea, but Motonari had refused the idea on tactical grounds. For Miyajima to be a viable base of operations, Sakurao Castle – the nearest fort on the mainland to Miyajima – would also have to be held. Should Sakurao fall, any army on Miyajima risked being isolated. Yet Mōri's own insight into the weakness of the Miyajima position led him to form a plan in which he would lure Sue into this exact trap. Naturally, such a tactic would require Sue's unwitting cooperation, and for inducement, Motonari immediately gave orders that Miyajima was to be occupied. A fort, Miyao Castle, was thrown up quite near the Itskushima shrine and Motonari proclaimed publicly his woe that it would not hold out long against an attack. In September, Sue fell into the trap. He landed with the bulk of his army on Miyajima and assaulted the (intentionally) thin defenses of Miyao Castle. When the island had been secured (including the capture of Sakurao), Sue threw up a few fortifications on To-no-oka (Pagoda Hill) and sat down to plot strategy. From his point of view the capture of Miyajima was a strategic boon. From this secure springboard he could embark to almost any point along the Aki coast, as well as Bingo Province. Since the following autumn, Mōri had assumed a largely defensive posture, and Sue had some reason to feel comfortable in his new forward headquarters. Sue thus made his second great mistake – he became complacent.

Mōri put his strategy into effect. Within a week he retook Sakurao Castle and played his trump card – the Murakami pirates. Gathering the pirates' naval strength, he set out to surprise Sue on Miyajima, and picked a perfect night on which to do so. On October 1, after dark and in a driving thunderstorm, Motonari and his sons put to sea. So the Battle of Miyajima began. As a diversion, Kobayakawa Takakage sailed straight past the Sue positions on To-no-oka while Motonari, Mōri Takamoto, and Kikkawa Motoharu landed just to the east and out of sight. Takakage doubled back and landed at dawn, attacking the Sue forces practically in the shadow of Miyajima's great torii gate. Motonari then assaulted the confused Sue troops from behind, and the result was a rout for Sue Harukata, who committed suicide at Oenoura, a small island inlet. Many of his troops followed suit, and for Motonari, the battle was utterly decisive.

Motonari had annihilated the Sue who had aspired to take the place of the Ōuchi clan. While it would take the Mōri until 1557 to force Ōuchi Yoshinaga to commit suicide and years longer to completely bring Suo province and Nagato province under Mōri's control, Motonari was now the most powerful lord in western Japan.

In the same year 1557, Motonari once again announced his retirement and Takamoto inherited the formal leadership of the clan. Even after Motonari's retirement, he continued to wield actual control over the clan's affairs.

Conflict with Amago

In 1554, Motonari's intrigues led to the death of Amago Kunihisa in battle with Amago Haruhisa. Kunihisa, the son of Amago Tsunehisa, led a faction named the Shingūtō (新宮党) after the town, Shingu, where it was based. He had been trusted with military matters by his father Tsunehisa but he often looked down upon those who did not do well on the battlefield and was obnoxious from time to time. Supposedly, Motonari tricked Haruhisa into believing that Kunihisa and Era Fusahide (江良房栄) intended to take over the Amago clan. The circumstances may have been aggravated by Kunihisa's arrogance towards young Haruhisa. The death of Kunihisa and the purge of the Shingūtō weakened the Amago clan considerably.

In 1556, Yamabuki Castle (山吹城) was captured by the leader of the Amago clan, Amago Haruhisa, and Motonari lost control of the Iwami Ginzan Silver Mine.

When Haruhisa died in 1560, his son, Amago Yoshihisa, succeeded as head of the Amago. The shōgun, Ashikaga Yoshiteru wished for peace between the Amago and Mōri clans, but Motonari ignored his plea and invaded Izumo Province in 1562. So began the Second Siege of Toda Castle.

Second Siege of Toda castle

The Second Siege of Toda Castle lasted from 1562 to 1563. When Motonari attacked Amago Yoshihisa at Toda Castle, Yoshihisa executed his retainer, Moriyama Hisakane (宇山久兼), whom Yoshihisa feared would betray him. This caused most of his remaining troops to desert, and later Amago surrendered to Motonari. Yoshihisa was permitted to become a monk and was held captive at Enmei-ji. With the head of the Amago clan gone, the clan members were forced to serve as retainers to other daimyo. As a monk, Yoshihisa changed his name to Yurin (友林). After Mōri Terumoto became the head of Mōri clan, he became a retainer under Terumoto.

After defeating the Amago clan in Izumo Province, Motonari had become lord of eight provinces of the Chūgoku region. However, Amago Katsuhisa, son of Amago Masahisa (尼子誠久), led a remnant of the clan in rebellion with support from Yamanaka Yukimori.

Motonari's eldest son, Mōri Takamoto, while en route to attack the Amago clan in 1563, died of a sudden disease, though assassination by poison was suspected. Saddened and angered by his death, Motonari ordered all those whom he thought responsible to be punished. Takamoto's son and Motonari's grandson Mōri Terumoto was selected as Motonari's heir, but Motonari continued to wield the true power over the Mōri clan.

In 1570, Terumoto defeated Amago Katsuhisa at the Battle of Nunobeyama. Katsuhisa then fled to the Oki Islands. In 1578, Katsuhisa returned from the Oki Islands and captured Tajima and Inaba Provinces. He then occupied Kozuki Castle for Oda clan under Toyotomi Hideyoshi, and defended it against the Mōri clan. Later, he was attacked by Kobayakawa Takakage and Kikkawa Motoharu, defeated and forced to commit suicide.

Conflict with Ōtomo

After Ōuchi Yoshinaga, Otomo Sorin's younger brother, was forced to commit suicide by the advance of Mōri forces in 1557, Mōri Motonari captured Yoshinaga's Moji fortress in 1558. In response, Otomo Sorin recaptured the castle in September 1559, but the Mōri, led by Kobayakawa Takakage and Ura Munekatsu, quickly took the castle back. In 1561, forces under Ōtomo Sōrin attacked the Moji castle in alliance with the Portuguese, but the assault failed, and the castle finally remained in Mōri possession.

However, Motonari's advance against the Ōtomo was checked by the 1568 alliance between the Amago and Ōtomo clans. In 1569, Mōri Motonari led the assault on the Ōtomo clan's Tachibana castle which was held by Tachibana Dosetsu. Motonari won and captured the castle, but was driven back by Otomo Sorin in the Battle of Tatarahama that followed the siege. The battle of the Mōri clan with this larger allied force was part of Yamanaka Yukimori and Amago Katsuhisa's arrangement with Ōtomo. Motonari was distracted from his designs against the Ōtomo in Kyushu by his inability to defeat the Amago in Izumo province, some distance away in Honshu. As a result, he abandoned Tachibana castle and withdrew from his campaign against the Ōtomo.

Death

Motonari had been suffering from illness during the first half of the 1560s so the shōgun, Ashikaga Yoshiteru, sent him his doctor, Manase Dōsan (曲直瀬道三), to treat him. It seems that his physical condition improved temporarily and in 1567 his last son, Kadokikumaru (才菊丸) was born, later known as Kobayakawa Hidekane.

Mōri Motonari died on June 14, 1571, at Yoshida-Kōriyama Castle at the age of 74. The cause of death is said to be both esophageal cancer and old age.

Legacy

Motonari is remembered as one of the greatest Japanese warlords of the mid-16th century. Under his leadership the Mōri expanded from a few districts in Aki Province to rule over ten of the Chūgoku region's eleven provinces, and Motonari was known even in his day as a master of wiles and trickery, a warlord whose schemes won as many battles as his soldiers. He is best remembered for an event that probably never took place – the "lesson of the three arrows". In this parable, Motonari gives each of his sons an arrow to break. He then gives them three arrows bundled, and points out that while one may be broken easily, not so three united as one. The three sons were of course Takamoto, Motoharu, and Takakage, and the lesson is one that Japanese children still learn in school today. It is not known for certain if this actually happened or if it is an apocryphal legend. Motonari in fact had six other sons, two of whom appear to have died in childhood. The others included Motoaki, Motokiyo, Motomasa and (Kobayakawa) Hidekane.

Shiji Hiroyoshi, Kuchiba Michiyoshi, Kumagai Nobunao, Fukubara Sadatoshi, Katsura Motozumi, Kodama Naritada, Kokushi Motosuke, Hiraga Hirosuke, and Ichikawa Tsuneyoshi assisted Mōri Motonari in his rule. His greatest generals, however, were his own sons Kobayakawa Takakage and Kikkawa Motoharu, the 'Two Rivers' (a play on the 'kawa' characters in their names).

The well known "one line, three stars" emblem of the Mōri was inherited from the family's ancestor, Ōe no Hiromoto.

In addition to being a gifted general Motonari was also a noted poet and patron of the arts. Surviving letters written by his grandson Mōri Terumoto describe Motonari as a strict and demanding man with a sharp eye. He was succeeded by his grandson Terumoto, who was the son of the late Takamoto.

Family

In all, Motonari had nine sons and three daughters; four children were by his wife, three by a consort from the Nomi clan, and four by a consort from the Miyoshi clan.

There is also speculation that Ninomiya Naritoki (二宮就辰, 1546–1607) was Motonari's son with a woman from the Yada clan (矢田氏).

• Father: Mōri Hiromoto (毛利弘元, 1466–1506)

• Mother: name unknown, daughter of Fukubara Hirotoshi (福原広俊).

　• Brother: Mōri Okimoto (毛利興元, 1492–1516)

　• Brother: Aiō Mototsuna (相合元綱, d. 1524)

　• Brother: Kita Narikatsu (北就勝, d. 1557)

　• Brother: Mitsuke Motouji (見付元氏)

　　• Wife: Lady Myōkyū (妙玖夫人, 1499–1546), daughter of Kikkawa Kunitsune (吉川国経).

　　　• 1st son: Mōri Takamoto (毛利隆元, 1523–1563)

　　　　• Grandson: Mōri Terumoto (毛利輝元, 1553–1625)

　　　• 2nd son: Kikkawa Motoharu (吉川元春, 1530–1586)

　　　• 3rd son: Kobayakawa Takakage (小早川隆景, 1533–1597)

　　　• 1st daughter: name unknown, died young, taken hostage by the Takahashi clan (高橋氏) and later killed.

　　　• 2nd daughter: Goryū no Tsubone (五龍局, d.1574), wife of Shishido Takaie (宍戸隆家).

　　• Concubine: Nomi no Ōkata (乃美大方, d. 1601), daughter of Nomi Takaoki (乃美隆興).

　　　• 4th son: Hoida Motokiyo (穂井田元清, 1551–1597)

　　　• 7th son: Amano Motomasa (天野元政, 1559–1609)

　　　• 9th son: Kobayakawa Hidekane (小早川秀包, 1567–1601)

　　• Concubine: name unknown, daughter of Miyoshi Masataka (三吉致高) of the Miyoshi clan.

　　　• 5th son: Suginomori Motoaki (椙杜元秋, 1552–1585)

　　　• 6th son: Izuha Mototomo (出羽元倶, 1555–1571)

　　　• 8th son: Suetsugu Motoyasu (末次元康, 1560–1601)

　　　• 3rd daughter: name unknown, wife of Uehara Motomasa (上原元将).

Honours

• Junior Fifth Rank, Lower Grade (Ju go-i-no-ge, 従五位下), Aryō (右馬頭)

• Junior Fourth Rank, Upper Grade (Ju shi-i-no-jō, 従四位上), Aryō (右馬頭)

• Jibu-shō (治部少輔) - Second assistant to the Minister of Ceremonies

• Mutsu-no-kami (陸奥守)

• Junior Third Rank (ju san-mi, 従三位)

• Senior First Rank (shō ichi-i, 正一位) - April 2, 1908; posthumous

The 18 Generals of Mōri (毛利十八将)

• Kikkawa Motoharu (吉川元春, 1530–1586), second son of Motonari, with his brother they were known as "Mōri Ryōkawa", or "Mōri's Two Rivers" (毛利両川).

• Kobayakawa Takakage (小早川隆景, 1533–1597), third son of Motonari, with his brother they were known as "Mōri Ryōkawa", or "Mōri's Two Rivers" (毛利両川).

• Shishido Takaie (宍戸隆家, 1518–1592), married to one of Motonari's daughters, Goryū no Tsubone.

• Kuchiba Michiyoshi (口羽通良, 1513–1582), responsible for fighting in the San'in region and as an assistant to Kikkawa Motoharu.

• Fukubara Sadatoshi (福原貞俊, 1512–1593), maternal uncle of Motonari, son of Motonari's maternal grandfather, Fukubara Hirotoshi.

• Amano Takashige (天野隆重, 1503–1584), originally a vassal of the Ōuchi clan, switched to Motonari after the death of Ōuchi Yoshitaka. His wife was the sister of Fukubara Sadatoshi.

• Kumagai Nobunao (熊谷信直, 1507–1593), fought in nearly all of Motonari's battles.

• Kunishi Motosuke (国司元相, 1492–1592), fought with distinction at the Siege of Koriyama. Later, he was chosen as one of the five bugyō of the Mōri clan.

• Katsura Motozumi (桂元澄, 1500–1569)

• Kodama Naritada (児玉就忠, 1506–1562), Motonari valued his administrative skill. Motonari's bugyō along with Katsura Mototada (桂元忠). Under Mōri Terumoto he became one of the five bugyō.

• Yoshimi Masayori (吉見正頼, 1513–1588), originally a vassal of the Ōuchi clan, switched to Motonari after the death of Ōuchi Yoshitaka.

• Shiji Hiroyoshi (志道広良, 1467–1557), close with Motonari early when his brother Okimoto was clan head. Supported Motonari as successor to the leadership of the clan. Served as guardian of Motonari's first son, Takamoto.

• Awaya Motohide (粟屋元秀), was prized after the Battle of Arita-Nakaide by Motonari for his achievements.

• Awaya Motochika (粟屋元親, d. 1561), Motonari prized his skills with domestic affairs. Under Mōri Terumoto he became one of the five bugyō.

• Akagawa Motoyasu (赤川元保, d. 1567), imprisoned in his home under suspicion of the sudden death of Mōri Takamoto and later forced to commit suicide with his adopted son Akagawa Matasaburō.

• Watanabe Hajime (渡辺長, 1534–1612), saved Motonari's life at the First Siege of Toda Castle.

• Iida Motochika (飯田元親, d. 1535), second son of Kodama Motoyoshi (児玉元良), supported the succession of Motonari as clan head.

• Inoue Motokane (井上元兼, 1486–1550), escaped Motonari's purge of the Inoue clan because of his loyalty.

Other notable retainers

• Hayashi Narinaga (林就長, 1517–1605), karō (clan elder) of Motonari and bugyō under Mōri Terumoto. Ginzan-bugyō (mining official) at the Iwami Ginzan Silver Mine. Junior Fifth Rank, Lower Grade (Ju go-i-no-ge, 従五位下), Hizen-no-kami (肥前守). Diplomat of the Mōri clan along with Ankokuji Ekei.

• Ankokuji Ekei (安国寺恵瓊), diplomat of the Mōri clan along with Hayashi Narinaga. He was a Rinzai Buddhist monk. Executed by Tokugawa Ieyasu for fighting on the side of Ishida Mitsunari at the Battle of Sekigahara.

• Kikkawa Kunitsune, father-in-law of Motonari.

• Kikkawa Hiroie (吉川広家), son of Kikkawa Motoharu, grandson of Motonari. His mother was daughter of Kumagai Nobunao

• Kikkawa Motomune (吉川元棟), son of Kikkawa Motoharu, grandson of Motonari. His mother was daughter of Kumagai Nobunao

• Katsura Mototada (桂元忠), was a bugyō of Motonari.

• Hironaka Kataaki (弘中方明), also (弘中就慰)

• Fukubara Mototoshi (福原元俊), Junior Fifth Rank, Lower Grade (Ju go-i-no-ge, 従五位下), Dewa-no-kami (出羽守).

• Nomi Takaoki (乃美隆興), father of one of Motonari's concubines, Nomi no Ōkata.

• Nomi Munekatsu (乃美宗勝)

• Hiraga Hirosuke (平賀広相)

• Hiraga Motosuke (平賀元相）

• Sugihara Morishige (杉原盛重)

• Miura Mototada (三浦元忠)

• Sugi Motosuke (杉元相)

• Hirasa Nariyuki (平佐就之), Ginzan-bugyō (mining official) at the Iwami Ginzan Silver Mine.

• Ōhashi Hachizō (大橋八蔵), Ginzan-bugyō (mining official) at the Iwami Ginzan Silver Mine.

• Awaya Motomichi (粟屋元通), Bizen-no-kami (備前守).

• Murakami Takeyoshi (村上武吉), captain of the Murakami Navy (能島村上水軍).

• Murakami Motoyoshi (村上元吉), son of Murakami Takayoshi, captain of the Murakami Navy (能島村上水軍).

• Miyoshi Masataka (三吉致高), father of one of Motonari's concubines.

• Miyoshi Takasuke (三吉隆亮), brother of one of Motonari's concubines.

• Masuda Motonaga (益田元祥), married to the daughter of Kikkawa Motoharu.

• Uehara Motomasa (上原元将), married to Motonari's third daughter.

• Wachi Masaharu (和智誠春), was under suspicion of the sudden death of Mōri Takamoto.

• Hayashi Motoyoshi, (林元善, 1558–1609), first son of Hayashi Narinaga. Shima-no-kami (志摩守).

• Hayashi Nagayoshi (林長由), second son of Hayashi Narinaga. Jirōuemon (次郎右エ門). Retainer of Kobayakawa Takakage, moved to Nuta and changed his name to Ishibashi.

Motonaris castles

Province

• Yoshida-Kōriyama Castle (吉田郡山城), main castle of the Mōri clan and residence of Motonari.

• Tajihi-Sarugake Castle (多治比猿掛城), Motonari spent his youth in the castle.

• Suzuo Castle (鈴尾城), main castle of the Fukuhara clan, Motonari`s birthplace.

• Miiri-Takamatsu Castle (三入高松城), main castle of the Kumagai clan

• Goryu Castle (五龍城), main castle of the Shishido clan

• Katsura Castle (桂城), main castle of the Katsura clan

• Hinoyama Castle (日野山城), main castle of the Kikkawa clan

• Biwakō Castle (琵琶甲城), main castle of the Kuchiba clan

• Mibu Castle (壬生城)

• Funayama Castle (船山城)

• Nagamiyama Castle (長見山城)

• Toko no Yama Castle (鳥籠山城)

• Yagi Castle (八木城)

• Koi Castle (己斐城)

• Sato-Ginzan Castle (佐東銀山城)

• Sakurao Castle (桜尾城)

• Miyao Castle (宮尾城)

• Kusatsu Castle (草津城), main castle of the Kodama clan

Province

• Takayama Castle (高山城) main castle of the Kobayakawa clan until Kobayakawa Takakage moved their main castle to Niitakayama Castle

• Niitakayama Castle (新高山城) main castle of the Kobayakawa clan

• Mihara Castle (三原城) main castle of the Kobayakawa clan

• Hatagaeshiyama Castle (旗返城)

• Kannabe Castle (神辺城), main castle of the Sugihara clan

• Kashirazaki Castle (頭崎城), main castle of the Hiraga clan

• Kagi Castle (賀儀城), main castle of Ura clan Nomi Munekatsu

Other provinces

• Kōnomine Castle

• Gassantoda Castle

• Shikano Castle

• Odaka Castle : Sugihara Morishige

• Yamabuki Castle

• Kumano Castle : Amano Takashige

• Noshima Castle, main castle of the Noshima Murakami clan