Born
179
Died
251
Ancestral home
Xiaojing, Wen County, Henei (Zhaoxian Town, Wen County, Henan)
Book mentions
466
Roles:
general politician regent
Factions:
Cao Wei (primary)
Relationships:
Sima Lang Brother
Sima Juan Grandfather
Appears in 29 chapters:
  • Chapter 39 — At Jingzhou, The Son Of Liu Biao Thrice Begs Advice; At Bowang Slope, The Directing Instructor Plans His First Battle.
    Appointed literary secretary as Cao Cao absorbs the great offices - introduced by lineage alone: grandson of Sima Juan, son of Sima Fang, younger brother of Sima Lang, a man of Henei. The quietest debut of the book's longest game.
  • Chapter 67 — Cao Cao Conquers Hanzhong; Zhang Liao Terrorizes Xiaoyao.
    Sima Yi; backs Liu Ye's advice to push into Yi Province now; Cao Cao refuses the gamble.
  • Chapter 69 — Guan Lu Sees Things In The Book Of Changes; Five Loyal Subjects Die For Their State.
    Sima Yi; at Cao Cao's court.
  • Chapter 73 — Liu Bei Becomes The Prince Of Hanzhong; Guan Yu Marches To Attack Xiangyang.
    Sima Yi; first major counsel - proposes goading Sun Quan to attack Jingzhou to relieve Wei pressure. The strategy that produces the Lu Meng raid.
  • Chapter 75 — Guan Yu Has A Scraped-Bone Surgery; Lu Meng Crosses The River In White Robe.
    Sima Yi; on Cao Cao's council; with Jiang Ji presses the Sun Quan back-channel - let Wu attack Jingzhou.
  • Chapter 77 — Cao Cao Is Possessed At Luoyang; Guan Yu Manifests At The Jade Spring Mount.
    Sima Yi; advises Cao Cao to bury Guan Yu's head honourably so the vengeance goes to Wu, not Wei. The classic deflection move.
  • Chapter 78 — Treating A Headache, A Famous Physician Dies; Giving The Last Words, The Crafty Hero Departs.
    Sima Yi; senior on Cao Cao's deathbed council; positioned as the steady hand under Cao Pi.
  • Chapter 80 — Cao Pi Deposes The Emperor, Taking Away The Fortunes of Han; Liu Bei Assumes The Throne, Continuing The Heritage.
    Sima Yi; in the Wei court; senior official in the new dynasty.
  • Chapter 85 — The First Ruler Confides His Son To A Guardian; The Prime Minister Calmly Settles Five Attacks.
    Sima Yi; designs the Five-Route plan against Shu; the cool strategist behind Cao Pi's offensive. Defused by Zhuge Liang routing each of the five separately without ever assembling them in battle.
  • Chapter 86 — Using Words, Qin Mi Overcomes Zhang Wen; Setting Fire, Xu Sheng Defeats Cao Pi.
    Sima Yi; in the Wei court - rising.
  • Chapter 91 — Sacrificing At River Lu, The Prime Minister Marches Homeward; Attacking Wei, The Lord Of Wuxiang Presents A Memorial.
    Sima Yi; named regent at Cao Pi's death; despatched to govern Yongliang to control the western frontier - the post he will hold against Zhuge Liang's expeditions.
  • Chapter 94 — Zhuge Liang Defeats The Qiangs In A Snowstorm; Sima Yi Captures Meng Da By A Rapid March.
    Sima Yi; the chapter's pivot. Recalled to active command at Cao Rui's order; immediately moves on Xincheng and crushes Meng Da's planned defection from the inside before it can take effect - riding day-night to surprise Shen Yi's mole-action; Meng Da is beheaded by his own subordinates Shen Dan and Shen Yi who switch sides at the last moment. Sima Yi's classic strike-first style; Zhuge Liang's intended ally inside Wei evaporates in a week.
  • Chapter 95 — Ma Su's Disobedience Causes The Loss Of Jieting; Zhuge Liang's Lute Repulses The Army Of Sima Yi.
    Sima Yi; takes Jieting through Zhang He's siege of Ma Su; arrives at Xicheng; falls for Zhuge Liang's empty-city bluff and withdraws. The two great minds' draw - Zhuge Liang's wits saving him from Sima Yi's overcaution.
  • Chapter 96 — Shedding Tears, Zhuge Liang Puts Ma Su To Death; Cutting Hair, Zhou Fang Beguiles Cao Xiu.
    Sima Yi; in the Wei central command; sends Jia Kui to relieve Cao Xiu.
  • Chapter 97 — Sending A Second Memorial, Zhuge Liang Renews The Attack On Wei; Forging A Letter, Jiang Wei Defeats The Northern Army.
    Sima Yi; in the Wei command; reviewing Cao Zhen's deployments.
  • Chapter 98 — Pursuing The Shu Army, Wang Shuang Meets His Death; Raiding Chencang, Zhuge Liang Scores A Victory.
    Sima Yi; on the Wei command; the rising star against Zhuge Liang.
  • Chapter 99 — Zhuge Liang Defeats The Wei Army; Sima Yi Invades The West River Land.
    Sima Yi; takes overall command of the Wei front from the ailing Cao Zhen. Pursues a defensive strategy of refusing battle; Zhuge Liang tries every trick to draw him out. The long game begins; Sima Yi's caution will eventually break Zhuge Liang at Wuzhang Plains by attrition.
  • Chapter 100 — Raiding A Camp, The Shu Soldiers Defeat Cao Zhen; Contesting Array Battles, Zhuge Liang Shames Sima Yi.
    Sima Yi; engineers the Gou An rumour; loses the chance to capture Zhuge Liang on the retreat when the firelight bluff fools him.
  • Chapter 101 — Going Out From Longshang, Zhuge Liang Dresses As A God; Dashing Toward Saber Pass, Zhang He Falls Into A Snare.
    Sima Yi; against his judgment is goaded by Zhang He into pursuing - and loses Zhang He in the gorge. Continues the defensive game; refuses to engage Zhuge Liang in open battle.
  • Chapter 102 — Sima Yi Occupies The Banks Of River Wei; Zhuge Liang Constructs Mechanical Bullocks And Horses.
    Sima Yi; the great refusal. Cao Rui personally sends Xin Pi with the imperial flag-of-restraint to ensure Sima Yi doesn't engage, sealing his strategy. The plan: outlast Zhuge Liang. It works.
  • Chapter 103 — In Gourd Valley, Sima Yi Is Trapped; In Wuzhang Hills, Zhuge Liang Invokes The Stars.
    Sima Yi; narrowly escapes the Shangfang Valley fire when the storm breaks. Receives the women's clothes from Zhuge Liang and refuses to be goaded; the iron-nerved defensive game continues. Quietly examines the envoy and learns Zhuge Liang is barely eating, working day and night - concludes the campaign will end itself by Zhuge Liang's collapse.
  • Chapter 104 — A Falling Star: The Prime Minister Ascends To Heaven; A Wooden Statue: The Commander-In-Chief Is Terrified.
    Sima Yi; sees the great red star fall and rejoices, then advances; sees the Shu army withdraw in order with what appears to be a living Zhuge Liang at the front; panics and retreats over a dozen miles before learning he was tricked. The novel's last laugh against him.
  • Chapter 105 — The Lord of Wuxiang Leaves A Plan In The Silken Bag; The Ruler of Wei Removes The Bronze Statue With The Dew Bowl.
    Sima Yi; in the Wei command; takes the field briefly during the Liaodong rebellion of Gongsun Yuan; subdues it; consolidates his hold on the army.
  • Chapter 106 — Suffering Defeat, Gongsun Yuan Meets His Death; Pretending Illness, Sima Yi Deceives Cao Shuang.
    Sima Yi; the High Plains Tomb coup (Gaoping Ling). With Cao Shuang and the new emperor Cao Fang away at the imperial cemetery, Sima Yi (long feigning illness - receives Li Sheng with the famous bedridden-doddering act of dribbling porridge down his front to deceive the spies) suddenly seizes the capital. Closes the gates; secures Empress Guo's authority; charges Cao Shuang with treason. Cao Shuang surrenders on Sima Yi's promise of mercy; promptly executed with three clans wiped out. Sima Yi takes Wei. The coup that founds Jin.
  • Chapter 107 — The Ruler of Wei Hands Over The Power To Sima Yi; Jiang Wei Is Defeated At Ox Head Hills.
    Sima Yi; consolidates the coup; appoints his own men through the Wei government; dies of old age toward the chapter's end. Hands command to Sima Shi. The figure who has stalked Zhuge Liang through every late chapter passes to his sons.
  • Chapter 108 — In The Snow, Ding Feng Wins A Victory; At A Banquet, Sun Jun Executes A Secret Plan.
    Sima Yi; named in passing - already dead.
  • Chapter 109 — A Ruse Of A Han General: Sima Zhao Is Surrounded; Retribution For The House Of Wei: Cao Fang Is Dethroned.
    Sima Yi; named in passing - already dead.
  • Chapter 111 — Deng Ai Outwits Jiang Wei; Zhuge Dan Battles Sima Zhao.
    Sima Yi; named in passing - long dead.
  • Chapter 119 — The False Surrender: A Wit Scheme Becomes A Vain Plan; The Abdication: Later Seeds Learn From The Ancient.
    Sima Yi; named in passing - long dead.