生平

崭露头角

黄巾之乱时，东阿县县丞王度呼应乱军，在地方造反，更烧掉县中的仓库。东阿县令逾城逃走，城中吏民负老携幼向东逃到渠丘山。此时程昱尚在故乡，所以亦杂在难民当中，他派人去侦查王度行动，发现王度等人因为县城物资尽空不堪留守，于是走出城西五六里外屯军。程昱便向县中大户薛房等人说：「如今王度得到城郭也不能屯居，其状况如何有目共睹。他只不过想趁机虏掠财物，并没有充实军备作守城的打算。我们何不重夺县城稳守下去？东阿城高墙厚，粮食充足，如今若果回城找寻县令，共同坚守，王度必不能久待下去，那时向他攻击，王度便可破了。」薛房等人都表示赞同。

可是当时很多吏民都不肯依从程昱的建议，程昱无奈叹道：「愚民不可共计大事。」为了令所有县民都愿意行动，于是程昱密遣数骑在东山上高举旗幡，让所有县民望见，然后命薛房等人大呼「贼兵已经攻至」，继而乘势下山取城，吏民以为黄巾乱兵真的已经杀到身边，情急之下便跟随程昱及薛房同往城中走回去，众人终于找到县令，进入城中共同守城。不久王度等人前来攻城，不能攻破，正欲退走。此时程昱带领县民开城门追击，王度败走。东阿县方才得以保全。

令誉始著

初平年间，兖州刺史刘岱想召程昱出仕，程昱不肯答应。当时刘岱与袁绍、公孙瓒三家共亲，袁绍让妻儿留在刘岱领地，公孙瓒亦派遣从事范方带兵助刘岱守地。可是后来袁绍与公孙瓒决裂，在早期阶段公孙瓒曾经击破袁绍军队，乘势要求刘岱献出袁绍的妻儿，并迫其与袁绍绝交。另一方面，公孙瓒又向范方下令：「若刘岱不献上袁绍家小，就先行领兵回来。待我收拾了袁绍后，必定前来攻打刘岱。」

刘岱受到这个两难的困扰，连日不能表决，别驾王彧向刘岱进言：「程昱是个有谋略的人，能断大事。」刘岱于是礼召程昱问计，程昱说：「如果放弃袁绍这个近援而结交公孙瓒为远助，这等同求助于越国的人去拯救在面前遇溺的孩童般愚昧。而且，公孙瓒最终必非袁绍之敌，如今他虽稍胜袁绍军队，但结果必为袁绍所擒。如果纯粹被一朝一夕的形势所动摇，而不思虑长远的计划，将军您必败无疑。」刘岱恍然大悟后，听从其计，谢绝公孙瓒的要求。范方领兵归去，但在他会合公孙军之前，公孙瓒已被袁绍所破。

经此一役，刘岱深深佩服程昱的见识，于是向朝廷表奏程昱为骑都尉，程昱却以有病为由不肯就任。

审时度势

后来刘岱为黄巾乱军所杀。曹操兵临兖州，辟召程昱出仕，程昱毫不推托，一口答应。程昱即将赴任时，他的同乡都感到十分疑惑，对程昱说：「为何一直不愿意当官的你，这次会答应出仕呢？」程昱却只笑而不答。程昱初到曹营，曹操便跟他谈论大事，十分高兴，以程昱为寿张令。

后来曹操征讨徐州，令程昱与荀彧留守鄄城。其时张邈等军队发动叛乱，迎接吕布进入兖州，更引起四周郡县的响应，唯独程昱等人守著的鄄城、范县及东阿县三处不为所动。当时有从吕布军处投降的士兵指，吕布部下的陈宫、泛嶷将要带兵攻取东阿及范县，鄄城里的百姓都十分恐惧。荀彧向程昱说：「如今兖州作反，唯有此三城得以保全。陈宫等以重兵临城，如果不能同心结力，三城必定会有所动摇。您（指程昱）是本地吏民最信赖的人，如今请您去游说他们坚守下去，一定可以成功！」程昱答应后便迅即起行，先往范县。当时泛嶷军队已到范县，范县县令靳允经程昱鼓励后，安排伏兵刺杀泛嶷，一举成功。程昱又遣人占住仓亭的渡口，使陈宫军不能渡河进军。接著程昱离开范县，来到东阿，其时东阿令枣祗已经率领当地吏民拒城坚守。又有兖州从事薛悌与程昱协谋，终于守住了三城。曹操回到兖州后，知道此事，亲执程昱之手说：「若非程卿之力，吾无所归矣。」于是表奏程昱为东平相，屯于范县。

军计明亮

曹操与吕布在濮阳交战时，数度失利。其时又有蝗祸，于是双方暂时收兵。袁绍趁机游说曹操迁家人到邺城居住（作为人质），亦答应与其连和。当时曹操眼见兖州新失，军粮又将尽，正想答应袁绍要求。程昱见状立即向曹操进谏：「听说将军想遣家人迁往邺城，与袁绍连和，有这样的事吗？」曹操说：「是的。」程昱便说：「我认为将军您只是一时失了分寸而已，否则又怎会如此不深思熟虑呢？袁绍据有燕、赵之地，怀并吞天下之心，可是以他的智谋并不足以成事。将军自以为能在他底下做事吗？将军您有非一般的威望，可以像韩信、彭越他们这样臣服于他人吗？如今兖州虽残，尚有三城可守。能战之士，不下万人。以将军的神武，加上我和文若（荀彧字）等人的协助，绝对可以完成霸王之业。希望将军能慎重考虑！」曹操才打消了与袁绍结盟的想法。

汉献帝定都许昌后，以程昱为尚书。其时兖州尚未绥抚停当，于是又以程昱为东中郎将，领济阴太守，都督兖州事宜。当时据有徐州的刘备为吕布所袭，投奔曹操。程昱向曹操说：「我观察刘备，认为他是一个有雄才而甚得众心的人物，这人一定不甘为人下，不如尽早杀掉他。」曹操不听其言，更派遣刘备截击袁术，程昱与郭嘉便向曹操说：「主公前日不除掉刘备，如今更向他借兵，他必定会有异心的。」曹操闻言大悔，但已经追之不及了。事实证明，袁术病死后，刘备去到徐州，杀掉守城的车胄，举兵背反曹操。

不久，程昱升为振威将军。当时袁绍在黎阳，准备移兵南渡，而程昱却只带七百兵守著鄄城，曹操知道情况危急，命人告诉程昱，表示要增加二千兵前往鄄城助守。程昱不肯接受，说道：「袁绍拥兵十万之众，自以为所向无前。他见我领兵少，必然轻视此地，不来进攻。但如果增加了我的士兵，军备过多则会引起袁绍注意，在他的立场而言，鄄城势将成为他不可不攻之地，而以他的军队亦必定能成功攻陷此地。因此向这里添兵只会有损无益。希望主公不要过于疑虑！」曹操了解过他的分析后，听从其言。后来袁绍探知程昱守地兵少，果然不向该地进兵。曹操知道此事后，向贾诩道：「程昱的胆识，比起孟贲、夏育真是有过之而无不及啊！」不久，程昱纠合一夥在野的亡命之徒，组织成数千人的精兵队伍，与曹操会师黎阳，讨伐袁谭、袁尚。二袁破走后，程昱拜为奋武将军，封安国亭侯。

接著曹操征讨荆州，刘备投奔东吴求助。有人认为孙权必会杀掉刘备，程昱却认为：「孙权新任在位，尚未受到天下的重视。曹公无敌于天下，初举荆州，威震江表，孙权虽然有谋，亦不能独自抵挡。刘备一向有英名，关羽、张飞皆是力敌万人的豪杰，孙权必定会援助他们，藉其力以防御我军。当大难消除后，双方分道扬镳，刘备得到了实际资本，孙权就再也不能杀掉刘备了。」事后证明，他的见解完全正确!!

攻取荆州后，中原之地大致平定，曹军势力逐渐扩充。一次，曹操抚著程昱之背说道：「当初兖州之败，若非听从你的计谋，我又怎可以来到这里呢？」程昱答道：「所谓『知足不辱』（出自《道德经》第四十四章，指一个人只要懂得知足，就不会因为过份的贪婪而得到屈辱的收场），如今是我急流涌退的时候了。」于是正式表示从此缴还兵权，阖门不出。

善处人事

曹操征讨马超时，曹丕留守都城，程昱负责参知军事。当时田银、苏伯等于河间作反，曹丕遣将军贾信征讨。叛军中有千馀人请降，朝中大臣皆认为应按照旧法，尽诛降军，程昱却说：「以前之所以要诛杀投降者，是因为当时局势动荡，天下大乱，攻打贼人时采取『围而后降者不赦』的方针，目的在于向其它乱党显示不尽早投降的后果，让所有敌人都感到惧怕，未围先降，那以后用兵便不需要动辄围城。如今天下形势大致已经安定，而且今次的战事是发生在领土之内，这些都是不成气候的贼众，杀了他们也没有可以示威示惧的地方，失去了以往诛降的策略意义。因此我认为这些降兵不可诛杀；即使要诛杀他们，也要先询问曹公的意见。」可是当时的大臣都说：「军事方面我们可以自行下决定，毋须事事向曹公启奏啊！」程昱闻言后，不再作出回应。

直至朝议完结后，曹丕离开议堂，特地引见程昱，向其询问：「您似乎言犹未尽？」程昱方才表示：「所谓『可以自行下决定』的制度，是指面对临时之急，需要尽速立定决策的时候，才可以实行的。如今反贼已经被贾信制服，此事不会突发太过急剧的异变。因此老臣才不希望将军急于自作主张，做出专制的事情。」曹丕这才明白程昱的苦心，叹道：「程君真是考虑得十分周到啊！」他即时将河间叛变一事向曹操交代，曹操经居府长史国渊的进劝，果然下令不诛降者。曹操还都知道来龙去脉后，十分喜悦，向程昱说：「程卿不单止明于军事计略，亦善于处理别人父子之间的事情。」

生未其位

由于程昱个性刚戾，与同僚多有冲突不和。有人诬告程昱谋反，可是曹操对程昱的待遇却更加亲近。曹操担任魏公建立魏公国时，程昱担任卫尉（九卿之一），后来与中尉邢贞为了威仪方面的事情发生冲突，遭到罢免。后来文帝曹丕登基建立魏朝，程昱复为卫尉，进封安乡侯，增邑三百户，共计八百户。少子程延及孙儿程晓皆被封为列侯。

223年，贾诩逝世，当时朝廷正欲升程昱为三公之列，可是程昱却在此时去世。曹丕亦为之难过，追赠车骑将军，諡曰肃侯。太尉一职为锺繇接替。

人物

《三国志》记载程昱「长八尺三寸，美须髯」。也就是说，在形象方面，程昱的身高按现今尺寸达1米9以上，而且蓄有秀长的络腮胡子。性格方面，程昱虽然善于审视及分析形势，而且很有谋略，可是他的性格却相当刚强急躁，容易与人结怨。

逸闻

《魏书》记载：程昱少年时候，经常梦见自己登上泰山以两手捧日。程昱自觉奇异，曾向荀彧说出这事。在兖州动乱之时，全赖程昱奔走筹谋，鄄城等三个县城才得以保全。这时候荀彧把程昱之梦告诉曹操。曹操听后，便向程昱说：「卿当终为吾腹心。」当时程昱仍是叫作「程立」，曹操顺应梦兆，于其「立」字上加一个「日」字，「程立」于是正式改名为「程昱」。

郭颁《魏晋世语》中有一段：「初，曹操乏食，昱略其本县，供三日粮，颇杂以人脯，由是失朝望，故位不至公。」文中指，曹操与吕布争兖州时因蝗灾缺粮，程昱为解军粮之急，不但在自己的县城里（东阿县）强夺粮食，军粮中更颇杂以人肉乾。此残忍之举对程昱的声誉伤害颇深，结果导致毕生位不至三公。

家庭

子

• 程武，承袭程昱爵位

• 程延，封列侯

孙

• 程克，承袭程武爵位，子程良

• 程晓，魏黄门侍郎，后迁汝南太守

评价

• 王彧：「程昱有谋，能断大事。」（《三国志‧程昱传》）

• 荀彧：「君，民之望也。」（《三国志‧程昱传》）

• 曹操：「卿当终为吾腹心。」「程昱之胆，过于贲、育。」 「君非徒明于军计，又善处人父子之间。」（《三国志‧程昱传》）

• 陈寿：「昱性刚戾，与人多迕。」「程昱、郭嘉、董昭、刘晔、蒋济才策谋略，世之奇士，虽清治德业，殊于荀攸，而筹画所料，是其伦也。」（《三国志‧程昱传》）

• 朱敬则：「神人无功，达人无迹。张子房元机孤映，清识独流。践若发机，应同急箭；优游澹泊，神交太虚，非诸人所及也。至若陈平、荀彧、贾诩、荀攸、程昱、郭嘉、田丰、沮授、崔浩、张宾等，可谓天下之菁英。帷幄之至妙，中权合变，因败为功，爰自秦汉，讫于周隋。」

• 王溥：「魏晋以贾诩之筹策、贾逵之忠壮、张既之政能、程昱之智勇、顾雍之密重、王浑之器量、刘惔之鉴裁、庾翼之志略，彼八君子者。」

• 洪迈：「曹操牧兖州，州叛迎吕布，郡县八十城皆应之，唯鄄城、范、东阿不动，赖荀彧、程昱之力，卒全三城以待操，州境复安。古之人拔亡为存，转祸为福，如此多矣。」

• 陈亮：「以成魏之霸业者，昱、嘉之谋为多，而曹公尤痛惜嘉之死也。」

• 刘祁：「已而诸豪割据，士大夫各欲择主立功名，如荀攸、贾诩、程昱、郭嘉、诸葛亮、庞统、鲁肃、周瑜之徒，争以智能自效。」

• 郝经：「危哉！昭烈防不出数子之彀，操之遣拒袁术也，昱嘉昭皆以为不可遣，毒手莫施幸而扬去，料敌制胜卒使昭烈不得中原尺土。呜呼！数子何雠汉之深也。当是之时，魏有荀彧、荀攸、贾诩、程昱、郭嘉、董昭、刘晔、蒋济、司马懿为之谋，吴有张昭、周瑜、鲁肃、吕蒙、陆逊运其筹。」

民间艺术

《三国演义》中的程昱

• 在《三国演义》中，程昱登场于第十回〈勤王室马腾举义　报父雠曹操兴师〉。当时荀彧初投曹操，向曹操荐贤，他评价程昱为「兖州贤士」，曹操于是礼聘当时在山中读书的程昱出仕。程昱面见曹操时，又向曹操推荐郭嘉。

• 小说中，程昱是曹操手下其中一名最重要的谋臣。如正史一般，程昱跟从曹操以来，参与了攻打吕布、袁绍、刘备、孙权的大部份战事，一直出谋献策，表现出众。在第二十三回中，曹操接见名士祢衡，向其炫耀手下文臣武将时，曾说「荀彧、荀攸、郭嘉、程昱，机深智远，虽萧何、陈平不及也」，可是祢衡却评价程昱「可使关门闭户」而已。

• 刘备投靠曹操时，程昱曾劝曹操杀掉刘备，但曹操在听过郭嘉的意见后，决定放过刘备，其后更借给军马，遣刘备追击袁术，让刘备有机会重新独立。

• 第二十回中，程昱劝曹操乘著挟帝的威势行「王霸之事」；但于第二十四回却谏曹操勿行废立之事，避免失众望而启兵端。

• 曹操在徐州击溃了刘备军后，想招降独守孤城的关羽，张辽自荐为使。程昱设计利用徐州降兵引关羽出城，再围其于土山上，使其进退两难，其后张辽果然成功说服关羽暂投曹营。后来曹操与袁绍战于白马，绍将颜良极其勇猛，程昱建议召关羽出战，行一石二鸟之计，结果既击败了颜良，又令投靠了袁绍的刘备几乎因袁绍疑心而被杀。

• 仓亭之战中，程昱向曹操献「十面埋伏」之计，令袁绍军队一败涂地，元气大伤。

• 关羽千里走单骑时，程昱建议曹操杀掉关羽，勿纵虎为患，曹操不听，放走关羽；到了曹军兵败赤壁，曹操部领残军逃亡时，遇到伏兵于华容道的关羽，程昱分析关羽性格后，认为关羽为人有恩必报，于是建议曹操亲自向关羽攀谈，以求免难，结果成功动摇关羽的决心，曹操终于逃过厄运。

• 徐庶托名「单福」辅助刘备时，程昱识穿其真正身份，并使计把徐庶引到曹营。

• 赤壁之战中，程昱一直劝曹操留意「连环锁船」、「东南风起」等事，防范吴军阴谋，可是曹操却认为毋须忧虑，不加提防；后来吴将黄盖诈降，讹称要亲驶粮船归顺时，亦是程昱最早悉破其船并非粮船，必然有诈。

• 赤壁战后，曹操得知刘备占有荆州，心甚疑惧，程昱于是献策表奏周瑜、程普遥领荆州之郡，挑拨孙、刘二家互起争端，间接造成诸葛亮气死周瑜的局面。

• 诸葛亮首次伐魏时，以名将赵云为先锋，其势锐不可挡，令魏军大都督夏侯楙节节败退。当时程昱之子程武是魏军参军，他定下策略进行反击，令赵云一度身陷险境，几乎命丧。

影视形象

• 1994年电视剧《三国演义》：戴敬国、于连增饰演程昱

• 1996年电视剧《三国英雄传之关公》：聂秉贤饰演程昱

• 2004年电视剧《武圣关公》：李远权饰演程昱

• 2008年电影《赤壁》及《赤壁2：决战天下》：王早来饰演程昱

• 2010年电视剧《三国》：蒋昌义饰演程昱

• 2012年电视剧《回到三国》：陈荣峻饰演程昱

• 2013年电视剧《新洛神》：白志伟饰演程昱

• 2013年电视剧《曹操》：云峰饰演程昱

• 2017年电影剧《军师联盟》：柳玉林饰演程昱

动漫作品

• 三国演义

• 《横山光辉三国志》（横山光辉）

• 《苍天航路》（王欣太）

• 《火凤燎原》（陈某）

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 (泛嶷), 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 (枣祗) 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 (车胄; 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 (邢贞). 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 (田横), 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 (卫尉) 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.