生平

嶄露頭角

黃巾之亂時，東阿縣縣丞王度呼應亂軍，在地方造反，更燒掉縣中的倉庫。東阿縣令踰城逃走，城中吏民負老攜幼向東逃到渠丘山。此時程昱尚在故鄉，所以亦雜在難民當中，他派人去偵查王度行動，發現王度等人因為縣城物資盡空不堪留守，於是走出城西五六里外屯軍。程昱便向縣中大戶薛房等人說：「如今王度得到城郭也不能屯居，其狀況如何有目共睹。他只不過想趁機虜掠財物，並沒有充實軍備作守城的打算。我們何不重奪縣城穩守下去？東阿城高牆厚，糧食充足，如今若果回城找尋縣令，共同堅守，王度必不能久待下去，那時向他攻擊，王度便可破了。」薛房等人都表示贊同。

可是當時很多吏民都不肯依從程昱的建議，程昱無奈嘆道：「愚民不可共計大事。」為了令所有縣民都願意行動，於是程昱密遣數騎在東山上高舉旗幡，讓所有縣民望見，然後命薛房等人大呼「賊兵已經攻至」，繼而乘勢下山取城，吏民以為黃巾亂兵真的已經殺到身邊，情急之下便跟隨程昱及薛房同往城中走回去，眾人終於找到縣令，進入城中共同守城。不久王度等人前來攻城，不能攻破，正欲退走。此時程昱帶領縣民開城門追擊，王度敗走。東阿縣方才得以保全。

令譽始著

初平年間，兗州刺史劉岱想召程昱出仕，程昱不肯答應。當時劉岱與袁紹、公孫瓚三家共親，袁紹讓妻兒留在劉岱領地，公孫瓚亦派遣從事范方帶兵助劉岱守地。可是後來袁紹與公孫瓚決裂，在早期階段公孫瓚曾經擊破袁紹軍隊，乘勢要求劉岱獻出袁紹的妻兒，並迫其與袁紹絕交。另一方面，公孫瓚又向范方下令：「若劉岱不獻上袁紹家小，就先行領兵回來。待我收拾了袁紹後，必定前來攻打劉岱。」

劉岱受到這個兩難的困擾，連日不能表決，別駕王彧向劉岱進言：「程昱是個有謀略的人，能斷大事。」劉岱於是禮召程昱問計，程昱說：「如果放棄袁紹這個近援而結交公孫瓚為遠助，這等同求助於越國的人去拯救在面前遇溺的孩童般愚昧。而且，公孫瓚最終必非袁紹之敵，如今他雖稍勝袁紹軍隊，但結果必為袁紹所擒。如果純粹被一朝一夕的形勢所動搖，而不思慮長遠的計劃，將軍您必敗無疑。」劉岱恍然大悟後，聽從其計，謝絕公孫瓚的要求。范方領兵歸去，但在他會合公孫軍之前，公孫瓚已被袁紹所破。

經此一役，劉岱深深佩服程昱的見識，於是向朝廷表奏程昱為騎都尉，程昱卻以有病為由不肯就任。

審時度勢

後來劉岱為黃巾亂軍所殺。曹操兵臨兗州，闢召程昱出仕，程昱毫不推託，一口答應。程昱即將赴任時，他的同鄉都感到十分疑惑，對程昱說：「為何一直不願意當官的你，這次會答應出仕呢？」程昱卻只笑而不答。程昱初到曹營，曹操便跟他談論大事，十分高興，以程昱為壽張令。

後來曹操征討徐州，令程昱與荀彧留守鄄城。其時張邈等軍隊發動叛亂，迎接呂布進入兗州，更引起四周郡縣的響應，唯獨程昱等人守著的鄄城、范縣及東阿縣三處不為所動。當時有從呂布軍處投降的士兵指，呂布部下的陳宮、氾嶷將要帶兵攻取東阿及范縣，鄄城裡的百姓都十分恐懼。荀彧向程昱說：「如今兗州作反，唯有此三城得以保全。陳宮等以重兵臨城，如果不能同心結力，三城必定會有所動搖。您（指程昱）是本地吏民最信賴的人，如今請您去游說他們堅守下去，一定可以成功！」程昱答應後便迅即起行，先往范縣。當時氾嶷軍隊已到范縣，范縣縣令靳允經程昱鼓勵後，安排伏兵刺殺氾嶷，一舉成功。程昱又遣人佔住倉亭的渡口，使陳宮軍不能渡河進軍。接著程昱離開范縣，來到東阿，其時東阿令棗祗已經率領當地吏民拒城堅守。又有兗州從事薛悌與程昱協謀，終於守住了三城。曹操回到兗州後，知道此事，親執程昱之手說：「若非程卿之力，吾無所歸矣。」於是表奏程昱為東平相，屯於范縣。

軍計明亮

曹操與呂布在濮陽交戰時，數度失利。其時又有蝗禍，於是雙方暫時收兵。袁紹趁機游說曹操遷家人到鄴城居住（作為人質），亦答應與其連和。當時曹操眼見兗州新失，軍糧又將盡，正想答應袁紹要求。程昱見狀立即向曹操進諫：「聽說將軍想遣家人遷往鄴城，與袁紹連和，有這樣的事嗎？」曹操說：「是的。」程昱便說：「我認為將軍您只是一時失了分寸而已，否則又怎會如此不深思熟慮呢？袁紹據有燕、趙之地，懷併吞天下之心，可是以他的智謀並不足以成事。將軍自以為能在他底下做事嗎？將軍您有非一般的威望，可以像韓信、彭越他們這樣臣服於他人嗎？如今兗州雖殘，尚有三城可守。能戰之士，不下萬人。以將軍的神武，加上我和文若（荀彧字）等人的協助，絕對可以完成霸王之業。希望將軍能慎重考慮！」曹操才打消了與袁紹結盟的想法。

漢獻帝定都許昌後，以程昱為尚書。其時兗州尚未綏撫停當，於是又以程昱為東中郎將，領濟陰太守，都督兗州事宜。當時據有徐州的劉備為呂布所襲，投奔曹操。程昱向曹操說：「我觀察劉備，認為他是一個有雄才而甚得眾心的人物，這人一定不甘為人下，不如儘早殺掉他。」曹操不聽其言，更派遣劉備截擊袁術，程昱與郭嘉便向曹操說：「主公前日不除掉劉備，如今更向他借兵，他必定會有異心的。」曹操聞言大悔，但已經追之不及了。事實證明，袁術病死後，劉備去到徐州，殺掉守城的車冑，舉兵背反曹操。

不久，程昱升為振威將軍。當時袁紹在黎陽，準備移兵南渡，而程昱卻只帶七百兵守著鄄城，曹操知道情況危急，命人告訴程昱，表示要增加二千兵前往鄄城助守。程昱不肯接受，說道：「袁紹擁兵十萬之眾，自以為所向無前。他見我領兵少，必然輕視此地，不來進攻。但如果增加了我的士兵，軍備過多則會引起袁紹注意，在他的立場而言，鄄城勢將成為他不可不攻之地，而以他的軍隊亦必定能成功攻陷此地。因此向這裡添兵只會有損無益。希望主公不要過於疑慮！」曹操了解過他的分析後，聽從其言。後來袁紹探知程昱守地兵少，果然不向該地進兵。曹操知道此事後，向賈詡道：「程昱的膽識，比起孟賁、夏育真是有過之而無不及啊！」不久，程昱糾合一夥在野的亡命之徒，組織成數千人的精兵隊伍，與曹操會師黎陽，討伐袁譚、袁尚。二袁破走後，程昱拜為奮武將軍，封安國亭侯。

接著曹操征討荊州，劉備投奔東吳求助。有人認為孫權必會殺掉劉備，程昱卻認為：「孫權新任在位，尚未受到天下的重視。曹公無敵於天下，初舉荊州，威震江表，孫權雖然有謀，亦不能獨自抵擋。劉備一向有英名，關羽、張飛皆是力敵萬人的豪傑，孫權必定會援助他們，藉其力以防禦我軍。當大難消除後，雙方分道揚鑣，劉備得到了實際資本，孫權就再也不能殺掉劉備了。」事後証明，他的見解完全正確!!

攻取荊州後，中原之地大致平定，曹軍勢力逐漸擴充。一次，曹操撫著程昱之背說道：「當初兗州之敗，若非聽從你的計謀，我又怎可以來到這裡呢？」程昱答道：「所謂『知足不辱』（出自《道德經》第四十四章，指一個人只要懂得知足，就不會因為過份的貪婪而得到屈辱的收場），如今是我急流湧退的時候了。」於是正式表示從此繳還兵權，闔門不出。

善處人事

曹操征討馬超時，曹丕留守都城，程昱負責參知軍事。當時田銀、蘇伯等於河間作反，曹丕遣將軍賈信征討。叛軍中有千餘人請降，朝中大臣皆認為應按照舊法，盡誅降軍，程昱卻說：「以前之所以要誅殺投降者，是因為當時局勢動蕩，天下大亂，攻打賊人時採取『圍而後降者不赦』的方針，目的在於向其它亂黨顯示不儘早投降的後果，讓所有敵人都感到懼怕，未圍先降，那以後用兵便不需要動輒圍城。如今天下形勢大致已經安定，而且今次的戰事是發生在領土之內，這些都是不成氣候的賊眾，殺了他們也沒有可以示威示懼的地方，失去了以往誅降的策略意義。因此我認為這些降兵不可誅殺；即使要誅殺他們，也要先詢問曹公的意見。」可是當時的大臣都說：「軍事方面我們可以自行下決定，毋須事事向曹公啟奏啊！」程昱聞言後，不再作出回應。

直至朝議完結後，曹丕離開議堂，特地引見程昱，向其詢問：「您似乎言猶未盡？」程昱方才表示：「所謂『可以自行下決定』的制度，是指面對臨時之急，需要盡速立定決策的時候，才可以實行的。如今反賊已經被賈信制服，此事不會突發太過急劇的異變。因此老臣才不希望將軍急於自作主張，做出專制的事情。」曹丕這才明白程昱的苦心，嘆道：「程君真是考慮得十分周到啊！」他即時將河間叛變一事向曹操交代，曹操經居府長史國淵的進勸，果然下令不誅降者。曹操還都知道來龍去脈後，十分喜悅，向程昱說：「程卿不單止明於軍事計略，亦善於處理別人父子之間的事情。」

生未其位

由於程昱個性剛戾，與同僚多有衝突不和。有人誣告程昱謀反，可是曹操對程昱的待遇卻更加親近。曹操擔任魏公建立魏公國時，程昱擔任衛尉（九卿之一），後來與中尉邢貞為了威儀方面的事情發生衝突，遭到罷免。後來文帝曹丕登基建立魏朝，程昱復為衛尉，進封安鄉侯，增邑三百戶，共計八百戶。少子程延及孫兒程曉皆被封為列侯。

223年，賈詡逝世，當時朝廷正欲陞程昱為三公之列，可是程昱卻在此時去世。曹丕亦為之難過，追贈車騎將軍，諡曰肅侯。太尉一職為鍾繇接替。

人物

《三國志》記載程昱「長八尺三寸，美鬚髯」。也就是說，在形象方面，程昱的身高按現今尺寸達1米9以上，而且蓄有秀長的絡腮鬍子。性格方面，程昱雖然善於審視及分析形勢，而且很有謀略，可是他的性格卻相當剛強急躁，容易與人結怨。

逸聞

《魏書》記載：程昱少年時候，經常夢見自己登上泰山以兩手捧日。程昱自覺奇異，曾向荀彧說出這事。在兗州動亂之時，全賴程昱奔走籌謀，鄄城等三個縣城才得以保全。這時候荀彧把程昱之夢告訴曹操。曹操聽後，便向程昱說：「卿當終為吾腹心。」當時程昱仍是叫作「程立」，曹操順應夢兆，於其「立」字上加一個「日」字，「程立」於是正式改名為「程昱」。

郭頒《魏晉世語》中有一段：「初，曹操乏食，昱略其本縣，供三日糧，頗雜以人脯，由是失朝望，故位不至公。」文中指，曹操與呂布爭兗州時因蝗災缺糧，程昱為解軍糧之急，不但在自己的縣城裡（東阿縣）強奪糧食，軍糧中更頗雜以人肉乾。此殘忍之舉對程昱的聲譽傷害頗深，結果導致畢生位不至三公。

家庭

子

• 程武，承襲程昱爵位

• 程延，封列侯

孫

• 程克，承襲程武爵位，子程良

• 程曉，魏黃門侍郎，後遷汝南太守

評價

• 王彧：「程昱有謀，能斷大事。」（《三國志‧程昱傳》）

• 荀彧：「君，民之望也。」（《三國志‧程昱傳》）

• 曹操：「卿當終為吾腹心。」「程昱之膽，過於賁、育。」 「君非徒明於軍計，又善處人父子之間。」（《三國志‧程昱傳》）

• 陳壽：「昱性剛戾，與人多迕。」「程昱、郭嘉、董昭、劉曄、蔣濟才策謀略，世之奇士，雖清治德業，殊於荀攸，而籌畫所料，是其倫也。」（《三國志‧程昱傳》）

• 朱敬則：「神人無功，達人無跡。張子房元機孤映，清識獨流。踐若發機，應同急箭；優遊澹泊，神交太虛，非諸人所及也。至若陳平、荀彧、賈詡、荀攸、程昱、郭嘉、田豐、沮授、崔浩、張賓等，可謂天下之菁英。帷幄之至妙，中權合變，因敗為功，爰自秦漢，訖於周隋。」

• 王溥：「魏晉以賈詡之籌策、賈逵之忠壯、張既之政能、程昱之智勇、顧雍之密重、王渾之器量、劉惔之鑑裁、庾翼之志略，彼八君子者。」

• 洪邁：「曹操牧兗州，州叛迎呂布，郡縣八十城皆應之，唯鄄城、范、東阿不動，賴荀彧、程昱之力，卒全三城以待操，州境複安。古之人拔亡為存，轉禍為福，如此多矣。」

• 陳亮：「以成魏之霸業者，昱、嘉之謀為多，而曹公尤痛惜嘉之死也。」

• 劉祁：「已而諸豪割據，士大夫各欲擇主立功名，如荀攸、賈詡、程昱、郭嘉、諸葛亮、龐統、魯肅、周瑜之徒，爭以智能自效。」

• 郝經：「危哉！昭烈防不出數子之彀，操之遣拒袁術也，昱嘉昭皆以為不可遣，毒手莫施幸而颺去，料敵制勝卒使昭烈不得中原尺土。嗚呼！數子何讎漢之深也。當是之時，魏有荀彧、荀攸、賈詡、程昱、郭嘉、董昭、劉曄、蔣濟、司馬懿為之謀，吳有張昭、周瑜、魯肅、呂蒙、陸遜運其籌。」

民間藝術

《三國演義》中的程昱

• 在《三國演義》中，程昱登場於第十回〈勤王室馬騰舉義　報父讎曹操興師〉。當時荀彧初投曹操，向曹操薦賢，他評價程昱為「兗州賢士」，曹操於是禮聘當時在山中讀書的程昱出仕。程昱面見曹操時，又向曹操推薦郭嘉。

• 小說中，程昱是曹操手下其中一名最重要的謀臣。如正史一般，程昱跟從曹操以來，參與了攻打呂布、袁紹、劉備、孫權的大部份戰事，一直出謀獻策，表現出眾。在第二十三回中，曹操接見名士禰衡，向其炫耀手下文臣武將時，曾說「荀彧、荀攸、郭嘉、程昱，機深智遠，雖蕭何、陳平不及也」，可是禰衡卻評價程昱「可使關門閉戶」而已。

• 劉備投靠曹操時，程昱曾勸曹操殺掉劉備，但曹操在聽過郭嘉的意見後，決定放過劉備，其後更借給軍馬，遣劉備追擊袁術，讓劉備有機會重新獨立。

• 第二十回中，程昱勸曹操乘著挾帝的威勢行「王霸之事」；但於第二十四回卻諫曹操勿行廢立之事，避免失眾望而啟兵端。

• 曹操在徐州擊潰了劉備軍後，想招降獨守孤城的關羽，張遼自薦為使。程昱設計利用徐州降兵引關羽出城，再圍其於土山上，使其進退兩難，其後張遼果然成功說服關羽暫投曹營。後來曹操與袁紹戰於白馬，紹將顏良極其勇猛，程昱建議召關羽出戰，行一石二鳥之計，結果既擊敗了顏良，又令投靠了袁紹的劉備幾乎因袁紹疑心而被殺。

• 倉亭之戰中，程昱向曹操獻「十面埋伏」之計，令袁紹軍隊一敗塗地，元氣大傷。

• 關羽千里走單騎時，程昱建議曹操殺掉關羽，勿縱虎為患，曹操不聽，放走關羽；到了曹軍兵敗赤壁，曹操部領殘軍逃亡時，遇到伏兵於華容道的關羽，程昱分析關羽性格後，認為關羽為人有恩必報，於是建議曹操親自向關羽攀談，以求免難，結果成功動搖關羽的決心，曹操終於逃過厄運。

• 徐庶託名「單福」輔助劉備時，程昱識穿其真正身份，並使計把徐庶引到曹營。

• 赤壁之戰中，程昱一直勸曹操留意「連環鎖船」、「東南風起」等事，防範吳軍陰謀，可是曹操卻認為毋須憂慮，不加提防；後來吳將黃蓋詐降，訛稱要親駛糧船歸順時，亦是程昱最早悉破其船並非糧船，必然有詐。

• 赤壁戰後，曹操得知劉備佔有荊州，心甚疑懼，程昱於是獻策表奏周瑜、程普遙領荊州之郡，挑撥孫、劉二家互起爭端，間接造成諸葛亮氣死周瑜的局面。

• 諸葛亮首次伐魏時，以名將趙雲為先鋒，其勢銳不可擋，令魏軍大都督夏侯楙節節敗退。當時程昱之子程武是魏軍參軍，他定下策略進行反擊，令趙雲一度身陷險境，幾乎命喪。

影視形象

• 1994年電視劇《三國演義》：戴敬國、于連增飾演程昱

• 1996年電視劇《三國英雄傳之關公》：聶秉賢飾演程昱

• 2004年電視劇《武聖關公》：李遠權飾演程昱

• 2008年電影《赤壁》及《赤壁2：決戰天下》：王早來飾演程昱

• 2010年電視劇《三國》：蔣昌義飾演程昱

• 2012年電視劇《回到三國》：陳榮峻飾演程昱

• 2013年電視劇《新洛神》：白志偉飾演程昱

• 2013年電視劇《曹操》：雲峰飾演程昱

• 2017年電影劇《軍師聯盟》：柳玉林飾演程昱

動漫作品

• 三國演義

• 《橫山光輝三國志》（橫山光輝）

• 《蒼天航路》（王欣太）

• 《火鳳燎原》（陳某）

Incidents in hometown

Cheng Yu's original given name was "Li" (立) but he changed it to "Yu" (昱; literally "lifting the sun") after he had a dream about the sun on top of Mount Tai. He was from Dong'e County, which is in present-day Shandong. There is nothing recorded in history about his early life; he was known for his courage in the areas around his hometown when he was in his early 40s. When the Yellow Turban Rebellion broke out in the 180s, a county magistrate, Wang Du, burnt down the food stored in the warehouse and instigated his subordinates to seize the city. The county prefect escaped the city and went into hiding, while the town residents took their families eastward and camped beside a mountain. After receiving intelligence from his spies that Wang Du had moved out and camped 1.3 to 1.6 miles away from the city, Cheng Yu reported to and told a local parvenu, Xue Fang, that Wang Du must not have the ability to control the situation, so they should retrieve the prefect and reoccupy the city. Xue Fang agreed to Cheng Yu's plan, yet the commoners refused to comply, wherein Cheng Yu angrily said: "Stupid commoners lack the ability to plan." He then plotted with Xue Fang, and secretly sent several cavalry holding streamers to the hilltop, where they rode down toward the civilians. Xue Fang and his men then screamed upon seeing the riders, making the commoners mistake them for Yellow Turban rebels. Led by Xue Fang, the mass kept running until back into the city, where they realised that the rebels were not so terrifying and started to defend the city with the prefect, whom Cheng Yu found later.

Seeing the inhabitants had come back, Wang Du launched an attack, but was foiled by Cheng Yu's defences. After some time, Wang Du could no longer hold on and intended to move elsewhere. Cheng Yu then led a sudden attack when Wang Du was packing, dealing him a major blow which enabled the survival of Dong'e County.

In 192, Liu Dai, the Inspector of Yan Province, invited Cheng Yu to join his administration but Cheng Yu refused. At the beginning, Liu Dai had very good relationship with the warlords Yuan Shao and Gongsun Zan, wherein Yuan Shao sent his family to reside with Liu Dai while Gongsun Zan sent a detachment of elite cavalry to help Liu Dai fight the Yellow Turbans in the area; however, Yuan Shao and Gongsun Zan became bitter enemies later, and were way more powerful than Liu Dai, who was forced to pick a side. Liu Dai then sought advice from Cheng Yu, who told the former that asking for help from Gongsun Zan was like requesting someone to save a drowning child from afar. He further analysed that Gongsun Zan, who had recently gained a minor military victory over Yuan Shao, would eventually lose to the latter. Therefore, it was not wise to enjoy a short-term benefit without a careful long-term plan. Liu Dai agreed with Cheng Yu's speech and severed ties with Gongsun Zan, who ordered his cavalry in Yan Province to return to his base in You Province. Just as Cheng Yu had predicted, Gongsun Zan soon suffered a heavy defeat by Yuan Shao before his cavalry could even join the battle. Liu Dai then asked Cheng Yu to become his officer, and offered him the position of a Cavalry Commandant, but Cheng Yu again refused employment.

Coming to serve Cao Cao

However, without the assistance from Gongsun Zan's elite cavalry, Liu Dai was soon killed by the Yellow Turbans, and Cao Cao came forth to take over the province. Upon his arrival, Cao Cao sent Cheng Yu a letter concerning his presence in the government. Cheng Yu replied to Cao Cao that he accepted the offer right away, so the commoners asked Cheng Yu: "How can you change your attitude so snobbishly?" Cheng Yu laughed at them without comment. When Cheng Yu joined Cao Cao, he was only assigned as a prefect, a position far lower than the ones Liu Dai offered him in the past. Still, Cheng Yu was determined to follow Cao Cao, as evidenced by his defences against the warlord Lü Bu, who attacked Cao Cao's base while the latter was away on a campaign in Xu Province.

Performance in Lü Bus invasion

When Lü Bu claimed his rule over Yan Province, many people gave up resistance and joined him; only Juancheng, Dong'e and Fan counties did not yield. At the time, Cheng Yu was guarding Juancheng with Cao Cao's chief strategist, Xun Yu, who analysed that the defences could only be successful if the officials guarding the three counties worked together. Xun Yu then asked Cheng Yu to oversee the defence of Dong'e County because he could probably convince his hometown to fight with him. Thus, Xun Yu stayed behind to watch over the fortress, and Cheng Yu went to Dong'e County. On his way, Cheng Yu passed by Fan County, where Si Yi (氾嶷), an official under Lü Bu, was trying to persuade the prefect of Fan County to switch allegiance to his lord. Cheng Yu sought a meeting with the prefect and managed to persuade him to reject and kill Si Yi. When he arrived at Dong'e County, Xue Ti (薛悌) and Zao Zhi (棗祗) had already set up defences around the area, so Cheng Yu split his cavalry force out to take control of Cangting ford to block the advances of Lü Bu's strategist, Chen Gong. Xue Ti then formulated a strategy with Cheng Yu, which enabled the defences of the three counties until Cao Cao returned from Xu Province.

The year 194 was a hard time for Cao Cao, because in addition to losing several battles to Lü Bu around Puyang, a widespread famine also broke out in Yan Province (but this also forced Lü Bu to retreat). For once, Cao Cao thought about relinquishing his position in Yan Province, and prepared to surrender to Yuan Shao. Nevertheless, Cheng Yu rebuked Cao Cao by saying that he had a calibre greater than just being a subject under Yuan Shao, and it was shameful for a genius to submit to a man who only enjoyed an overvalued fame. Cheng Yu said to Cao Cao: "Even a mere warrior like Tian Heng knew about shame, how could you act so shamefully to surrender to Yuan Shao?" However, Cheng Yu's heroic speech was way easier to say than to do, because Cao Cao's army had already been running out of food. Nevertheless, not wanting to be disgraced, Cao Cao appeared to listen to Cheng Yu, but asked him to prepare three days' worth of supplies. Unprepared to be asked to deal with this problem, Cheng Yu insanely devised a very vicious strategy: he personally led an armed force to pillage his hometown and abducted his townsfolk, who would then be slaughtered like pigs for Cao Cao's army to feed on.

Liu Beis betrayal

After Lü Bu was forced to abandon Yan Province, Cheng Yu and Xun Yu advised Cao Cao to escort Emperor Xian, who was in dire straits, into territory under Cao Cao's control. After Emperor Xian made it to Xuchang (Cao Cao's base) from Luoyang, Cheng Yu was appointed as a Master of Writing in the Han central government but was soon promoted to be East General of the Household and appointed as the Administrator of Jiyin Commandery. In 198, Lü Bu took Xu Province from Liu Bei, who surrendered to Cao Cao for protection. Cheng Yu told Cao Cao that Liu Bei was an ambitious man with many admirers and that he would not be a subject for long, so he should be taken care of as soon as possible. Cao Cao refused under the rationale that he did not want the death of one individual to affect the decision of others who might yield to the Han central government.

The following year, Cao Cao, Sun Ce and others defeated the warlord Yuan Shu, who then attempted to head north to join his half-brother, Yuan Shao. Liu Bei volunteered to intercept Yuan Shu and was granted a sizable army to do his job. When Cheng Yu heard the news, he rushed to Cao Cao and protested: "It's arguable you turned down our suggestion to kill Liu Bei earlier, but it's a certainty that he will betray you if lent a force." Thus, Cao Cao regretted upon his decision and sent an envoy to call the troops back, but it was already too late. Liu Bei led his army east to Xu Province, killed Che Zhou (車胄; the provincial governor appointed by Cao Cao) and seized control of the province.

Cao Caos northern campaign

When Yuan Shao defeated Gongsun Zan and congregated the four provinces north of the Yellow River, he assembled an army of over 100,000 to declare war against Cao Cao. Cheng Yu was made a general and was stationed in Juancheng with 700 soldiers. Cao Cao then sent a letter to Cheng Yu and asserted to Cheng Yu that he would send 2,000 men as reinforcements. However, Cheng Yu replied: "Yuan Shao has 100,000 men and considers himself invincible. If he sees I only have such a small army, he will not attack easily. On the contrary, if my position is strong (enough to threaten his movement), then he will not be able to pass me by without attacking; if he attacks, he'll surely win, so it will be a mere waste to send in reinforcement. I hope you could understand my rationale and don't doubt on that." Cao Cao was happy that he did not need to send additional troops to Cheng Yu, and was able to defeat Liu Bei in Xu Province within a short time.

Three years after Cao Cao defeated Yuan Shao at the Battle of Guandu, Cheng Yu recruited and enlisted several thousand robbers and inhabitants of deep hills around Yan Province, and led them to rendezvous with Cao Cao in Liyang, where Cao Cao had set up a front line military operation base against Yuan Tan and Yuan Shang. Along with Li Dian, Cheng Yu transported grain to Cao Cao by ships. Once, the supply line was blocked by Gao Fan, the Administrator of Wei Commandery, who capitalised on the geographic advantage. Cao Cao then ordered Cheng Yu to abandon the waterway and transport through other routes. However, Li Dian reasoned with Cheng Yu that Gao Fan could be defeated because he was lightly guarded with a small army. Therefore, they violated Cao Cao's order, and landed the northern bank and defeated Gao Fan, resulting in the smooth delivery of military necessities.

Battle of Red Cliffs

In 208, Cao Cao accepted the surrender of Liu Cong, the governor of Jing Province, and sent a letter to the eastern warlord, Sun Quan, to inform the latter that he had assembled an 800,000 strong force in Jiangling, and was eager to meet Sun Quan in person. The majority believed that Sun Quan would surely kill Liu Bei and submit to Cao Cao, but Cheng Yu correctly analysed that Sun Quan would support Liu Bei to fight a desperate war. However, due to the fact that Cao Cao enjoyed an absolute advantage both in terms of military and economy; therefore he did not take Cheng Yu's counsel seriously, and Cao Cao held lavish banquets on his warships from time to time. Out of negligence, none of Cao Cao's officers knew that the wind direction would change a few days per year along the Yangtze River, and so they thought that the direction of the wind gave Cao Cao's side the advantage. While Cao Cao was certain that the allied forces could not make use of a fire attack, nevertheless the enemy commander, Zhou Yu, had Cao Cao's grand fleet reduced to ashes overnight.

Advice to Cao Pi

When Cao Cao went west to fight against Ma Chao and Han Sui, Cheng Yu was assigned as a strategist to Cao Cao's son Cao Pi, who was in charge of the capital. During the time that Cao Cao went west, some local gentries in Hejian Commandery rebelled. When Cao Pi sent a general to subdue the revolt, several thousand rebels offered to surrender after being besieged. A meeting was held within the court to decide whether the surrender of the rebels should be accepted or not. Many participants of the discussion proposed to reject the surrender, because Cao Cao once issued a fiat that those who surrendered after being besieged should be executed. Cheng Yu opposed and said, "The reason why Cao Cao set such an expedient rule was that he was fighting against numerous enemies in a chaotic time. To execute those who surrender after being besieged could intimidate other potential enemies, and encouraged early submissions; subsequently, we did not need to lay siege every time. However, the territory under our control is now stabilised, and this battle happens within our own domain; so therefore these kinds of enemies will surely surrender, and killing them will not threaten other enemies. Thus, to kill the rebels now is not the primary focus of Cao Cao's rule. I suggest that their surrender be accepted; if you must execute them, then please inform master Cao first." The feckless audience simply ignored Cheng Yu's rationale, and vindicated their choice by claiming that they had the autonomy over military issues and that it was not necessary to report every single provision. Cheng Yu remained in silence and the officers left the meeting. After the exodus, Cao Pi specifically consulted Cheng Yu to see if he held any thought back in the discussion, wherein Cheng Yu replied, "The reason why Commandants and Commanders were given autonomic power is because frontline military issues are so imminent that decisions must be made immediately. But the surrendered rebels are enfettered by your general, and have no way to mutiny. That is why I don't want to see you use (abuse) your authority. Feeling delighted by Cheng Yu's support, Cao Pi changed his mind and reported the issue to Cao Cao, who ordered the surrendered rebels to be spared. As Cheng Yu expected, the bond between Cao Pi and his father, Cao Cao was strengthened as a result of their correspondence. After Cao Cao returned from his expedition, he particularly expressed his gratitude to Cheng Yu by claiming Cheng Yu to be an intelligent man who not only excelled in tactics but also knew how to manage the relationship between father and son.

Later life and death

Cheng Yu went into semi-retirement after losing to his political rival, Xing Zhen (邢貞). What was worse for him was that much invectives were done to Cheng Yu after his downfall, and someone even accused him of harbouring the intention of rebelling, but Cao Cao did not further investigate his once trusted aide; in contrast, he gave Cheng Yu more monetary rewards. Cheng Yu remained as a commoner and seldom left his home until Cao Pi usurped the throne from Emperor Xian in 220. Cheng Yu was re-instituted as the Minister of the Guards and earned a tax revenue from a marquisate composed of 800 taxable households. Since Cao Pi intended to make Cheng Yu a duke, a discussion was made in regard to the issue, but Cheng Yu died before the decision would be settled. He was given the posthumous title "Marquis Su" for his inviolable reverence (See Xing Zhen's case in the following section). Both his young son Cheng Yan and grandson Cheng Xiao were made Marquis, and Cheng Yu was succeeded by his eldest son, Cheng Wu (程武) after death. His grandson Cheng Xiao became a well-known scholar later.

Appraisal

Despite being famous for his paradoxes, Cheng Yu tended to belittle others in his speeches. For once, he inveighed Cao Cao as inferior to the likes of Tian Heng (田橫), who was a mere warrior, when he tried to dissuade Cao Cao from surrendering to Yuan Shao. He also used to call his townsfolk "stupid commoners".

Cheng Yu was a recalcitrant old man, and his hidebound characteristic compelled him to quarrel with others on a frequent basis. There is a quaint incident about how he entered a predicament when he offended Xing Zhen. When Cao Cao was first enfeoffed as a vassal by Emperor Xian, he appointed Cheng Yu as the Minister of the Guards (衛尉) in his vassal state, while Xing Zhen was appointed as the Commandant of the Capital (中尉). However, Cheng Yu had a rabid quirk in pontificating his dominance, and he purposely flaunted in front of Xing Zhen, who reported his invidious behaviour to Cao Cao. As punishment, Cheng Yu was stripped of his position.

Although ingeniously intelligent, Cheng Yu was of a perverse and hardhearted nature. Once, he ransacked his hometown, Dong'e County, and kidnapped his own townfolk to feed Cao Cao's army in an act of cannibalism. It was recorded that Cheng Yu would have the abducted cut into pieces to mix with rice, so the soldiers would enjoy their prized meals.

In Romance of the Three Kingdoms

In the 14th-century historical novel Romance of the Three Kingdoms, Cheng Yu offered a ruse in order to get Xu Shu to serve Cao Cao. At the time Xu Shu was serving as rival Liu Bei's key strategist and managed to score a major victory against Cao Cao's officers Lü Kuang, Lü Xiang and Cao Ren. Exploiting the fact that Xu Shu was an extremely filial son, Cheng Yu suggested to Cao Cao that Cao Cao hold Xu Shu's mother hostage and force Xu Shu to leave Liu Bei and serve Cao Cao. Cheng Yu wrote a fake letter to Xu Shu and successfully tricked Xu Shu to come to Xuchang. Ironically, Xu Shu's mother committed suicide after seeing her son fall for such a ruse and leaving a righteous person like Liu Bei to serve under the ruthless Cao Cao. Prior to the Battle of Red Cliffs, Cheng Yu had predicted that Sun Quan's forces would use fire to attack Cao Cao's naval fleet. However, Cao Cao did not heed his advice seriously as the winds were to their advantage then. After Cao Cao's major defeat, Cheng Yu was one of the few advisers who stood by Cao Cao all the way during their escape.