Sima Shi () (208 – 23 March 255), courtesy name Ziyuan, was a military general and regent of Cao Wei during the Three Kingdoms period of China. In 249, he assisted his father Sima Yi in overthrowing the emperor Cao Fang's regent Cao Shuang, allowing the Sima family to become paramount authority in the state, and he inherited his father's authority after his father's death in 251. He maintained a tight grip on the political scene and, when the emperor, Cao Fang, considered action against him in 254, had him deposed and replaced with his cousin, Cao Mao. This tight grip eventually allowed him to, at the time of his death in 255 after just having quelled a rebellion, transition his power to his younger brother, Sima Zhao, whose son Sima Yan eventually usurped the throne and established the Jin dynasty. After Sima Yan became emperor, he, recognising Sima Shi's role in his own imperial status, posthumously honoured his uncle as Emperor Jing of Jin (景帝), with the temple name Shizong (世宗). Early life Sima Shi was born in 208. He was Sima Yi's oldest son, born of Sima Yi's wife, Zhang Chunhua (張春華). When he was young, he was known for the elegance in his conduct and his intelligence, earning him a reputation equal to that of Xiahou Xuan and He Yan, with He Yan having gone as far as to once state: "The only person who could have the great achievements under the heaven is probably Sima Ziyuan." Sima Shi did not occupy any official position until he was 30 years old. It is likely that he was among the young intellectuals who were banned by Cao Rui from holding official position due to the fuhua an case. Between 237 and 239, Sima Shi was appointed as Cavalier Attendant-in-Ordinary (散騎常侍). Unfortunately, his career still did not progress smoothly as his family was Cao Shuang's opposition. He finally received some promotions to the post of Military Protector of the Palace (中護軍) through some political concession. Sina Shi's first wife, Xiahou Hui died in 234; they had five daughters together. How she died was disputed. Her biography in Book of Jin indicated that she eventually realised that her husband was not loyal to Wei; Sima Shi too became wary of her, due to her familial ties with the royal Cao clan of Wei. In 234, Xiahou Hui died after being