Sima Yi
Also known as Sima Yi 司马懿 · Zhongda 仲达 · posthumous Emperor Xuan of Jin 晋宣帝
- Dates
- 179–251
- Era
- Three Kingdoms, Cao Wei; the Sima path to Jin
- Role
- Wei commander who outlasted Zhuge Liang and seized the Cao regency
Sima Yi would not give Zhuge Liang the battle he needed, then pretended to be dying and took Wei's government at the Gaoping Tombs.
Who was Sima Yi?
Sima Yi was the Wei general and minister who fought Zhuge Liang by refusing battle, then destroyed the Cao regency by pretending to be too ill to move. He was born in 179 into a great family of Henei. He served Cao Cao and, more decisively, Cao Pi and Cao Rui. Jin sources say he once pleaded illness to avoid Cao Cao's early summons. That story flatters a family that later replaced Wei. The feigning to remember is the one in 249. He was never emperor. His grandson Sima Yan took the Wei abdication in 266 and founded Jin, and the new dynasty honoured Sima Yi after death as Emperor Xuan.
Against Zhuge Liang's northern campaigns he defended Wei's west and, at the Wuzhang Plains in 234, refused battle. A gift of women's clothes did not draw him out, and Zhuge Liang died in that stalemate. In 249 he was co-regent with Cao Shuang for the child emperor Cao Fang, until Cao Shuang pushed him aside and Sima Yi acted senile. When Cao Shuang left Luoyang with the emperor for the Gaoping Tombs, Sima Yi closed the city, took the army, and broke the promised pardon. Cao Shuang's clan was killed. Wei kept its emperors, and the Sima family held the state.
Key ideas
持重
Refuse the battle the enemy needs
At Wuzhang he would not fight a Shu army that had marched a long supply line and needed a decision. Patience here is a weapon with a date on it, and when Shu's food and its chancellor ran out, Wei had won without the pitched battle.
假痴
Feign incapacity
Stratagem 27, feign madness and keep your wits, cites him twice: accepting the insult of women's clothes to wear Shu down, and playing the invalid before the Gaoping coup. The second is the cleaner case, and he looked finished until the day was fixed.
Take the regency, leave the reign title
He took military power in 249, staffed the court with his sons, and died in 251 without proclaiming a dynasty. Sima Shi and Sima Zhao continued the hold, and Sima Yan founded Jin in 266.
Famous episodes
The headdress at Wuzhang
History234
Zhuge Liang, failing to draw him out, sent women's clothing to call him a coward. Sima Yi wore the insult and asked Luoyang for leave to fight, knowing the petition would take time. Shu buried its chancellor that season. The stratagem commentary files the headdress under feigned incapacity, and the campaign record is history: he declined the battle.
A dead Zhuge and a living Sima
History234
After Zhuge Liang's death in 234 the Shu army withdrew, Sima Yi pursued, and the columns turned with drums as if to attack, so he stopped. People said a dead Zhuge had put a living Zhongda to flight, and he treated the joke as a reason to have respected the risk. Stratagem 21, the cicada shedding its shell, uses this retirement. The pursuit and the turn are in the historical record.
The Gaoping Tombs
History249
Sima Yi stopped attending court and let Cao Shuang's man see him as a dying dotard who could not hold a cup. When Cao Shuang accompanied Emperor Cao Fang to the Gaoping Tombs outside Luoyang, Sima Yi seized the capital and the army. Cao Shuang surrendered on a promise of safety and was then killed with his people. This is the Gaopingling incident, the start of the open Sima supremacy, and stratagem 27 points at it for a reason.
Myths vs facts
He was a coward who never dared to face Zhuge Liang.
He fought the northern campaigns as Wei's defender and chose, at Wuzhang, not to grant the battle Shu needed. Zhuge Liang died during that refusal. Avoiding a disadvantageous fight is the strategy, not a gap in the record.
The empty fort shows Zhuge Liang made a fool of him whenever they met.
The scene is the novel, chapter 95, built on an anecdote Pei Songzhi already doubted. Sima Yi's historical dealings with Zhuge Liang are the western defence and the stalemate of 234.
Sima Yi founded the Jin dynasty.
He seized the Cao regency in 249 and died in 251. His grandson Sima Yan accepted Wei's abdication and founded Jin in 266. Sima Yi cleared the way, and he did not take the throne.
Takeaways
- Refuse the battle your opponent needs more than you do.
- Look finished only when the blow is already timed.
- Credit the grandson who founds the dynasty, and the man who cleared it.
Related stratagems
Rivals and connections
Sources
- Jin shu 晋书, Annals of Emperor Xuan
- Chen Shou, Records of the Three Kingdoms 三国志
- Romance of the Three Kingdoms 三国演义, ch. 95 (novel, 14th c.)