Sima Shi (pronunciationⓘ) (208 – 23 March 255),[1][2][3] courtesy name Ziyuan, was a military general and regent of Cao Wei during the Three Kingdoms period of China.

It is likely that he was among the young intellectuals who were banned by Cao Rui from holding official positions due to the "fuhua an" (浮华案) incident.

He argued that at this point, Sima Yi had just earned Cao Rui's trust, and showed no signs of disloyalty; his sons had no reasons to be disloyal as well.

Sima Shi would go on to rule the government effectively and impartially, ordering that all officials recommend talents to him, that they define the hierarchical ranks, take care of the impoverished and the orphaned, and deal with the delayed personnel affairs.

[8] In late 251, Deng Ai, the Grand Administrator of Chengyang, submitted a memorial to the court in which he stated that the Xiongnu under Liu Bao were growing too powerful, and therefore proposed a method of giving the Xiongnu under Liu Bao titles and awards, so as to divide and weaken them, and to further settle them somewhere further away from the Chinese citizens and to reeducate them on Chinese cultural traditions, a proposal to which Sima Shi agreed to.

It was once proposed to him to alter the existing constitutions, to which he responded: "A poet used to praise those who ‘abide by the principles of the Heavenly Lord and appear as if they know nothing themselves’.

In 254, Sima Shi made a violent move to consolidate his power, at Cao Fang's expense.

Cao Fang had aligned himself with the minister Li Feng (李豐), and Sima Shi had growing suspicions that they were plotting against him.

[21] Cao Mao, although 14 years old at the time, was known for his intelligence, and Empress Dowager Guo might have believed that he, alone of the princes and dukes, might have had a chance of counteracting the Simas.

Despite Empress Dowager Guo's intentions and Cao Mao's own intelligence, they made very little impact in trying to stem the tide of the Simas' growing power.

In reaction to the removal of Cao Fang, the general Guanqiu Jian, in 255, as the commander in the important eastern city of Shouchun (壽春; in present-day Lu'an, Anhui), along with another general Wen Qin (文欽), raised a rebellion against the Simas,[22] but were quickly crushed by Sima Shi's army.

[26] At the urging of Wang Su, Fu Gu (傅嘏), and Zhong Hui,[27] he led the troops himself,[28] which was important in the victory against Guanqiu Jian, but during one of the raids made by Wen Qin's son Wen Yang (文鴦), Sima Shi, in his anxiety, aggravated the eye that he had just had the operation in—causing his eye to pop out—and his conditions soon deteriorated greatly.

In 264, Zhao considered making You his heir to pass the succession back to Shi's line, but in the end, opted for his own eldest son, Sima Yan, who founded the Western Jin dynasty in 266.

Chronicles of the Three Kingdoms, Achilles Fang.The taishou of Cheng-yang Dent Ai sent up his opinion: “The Rong and Di barbarians have the hearts of beasts.

Therefore, in the time of King Xuan of Zhou there was the incursion of the Xianyun; and the Han Emperor Gaozu suffered adversity under them at Pingcheng.

Since the shan-yu came to the interior of China, the barbarians have lost their leader, and lack a ruler to control their unity or disunity.

Cleave their territory and weaken their force, give them posthumous honors – this is the best plan for defense of the frontiers.” He further set forth how those of the barbarians who were living together with the Chinese people should be gradually segregated and made to live outside the Chinese people, so they would respect the teachings of modesty and shame, and to obstruct the way to wantonness and villainy.

The wounded and sick soldiers wandered on and dragged themselves along the roads, some stumbling to their deaths in ditches and holes, some being captured and made prisoners.

Chronicles of the Three Kingdoms, Achilles Fang.During the two years when he served as zhongshu ling, Li Feng was frequently given private audience by the Emperor, no one knowing what they said.

Chronicles of the Three Kingdoms, Achilles Fang.On the day gengxu (March 27), Li Tao, Xiahou Xuan, Zhang Qi, Su Shuo, Yue Dun and Liu Xian were put to death, and their relatives to the third degree were all annihilated.

His attendants advised the Emperor to kill Sima Zhao when the latter came to take his leave, and seizing his troops, use them to repulse the Generalissimo.

Chronicles of the Three Kingdoms, Achilles Fang.On the day jiaxu (October 17), Sima Shi convened an assembly of officials in the name of the Empress Dowager, which he informed that the Emperor was conducting himself with unbounded license and with indecent intimacy toward singing-girls, and was not worthy to carry on the celestial line.

Let this be discussed in detail.” Chronicles of the Three Kingdoms, Achilles Fang.On the day dingchou (October 20), Sima Shi convened another assembly of officials and showed them the Empress Dowager's command.

On the day jiachen, Zhang Shu (張屬), a man of Anfengjin, killed Guanqiu Jian and sent his severed head to the capital.

Chronicles of the Three Kingdoms, Achilles Fang.At that time Sima Shi had recently had a tumor removed from his eye, and the wound was serious.

Chronicles of the Three Kingdoms, Achilles Fang.Only Wang Su, the shangshu Fu Ji, and the zhongshu Zhong Hui, advised Sima Shi to go in person.

Should the subordinate generals fight unsuccessfully and the tide be turned against you, then your cause will be ruined.” Sima Shi jumped up from his seat and said, “I shall go in spite of my ailment.” Chronicles of the Three Kingdoms, Achilles Fang.