Sima Zhou (227 – 12 June 283), courtesy name Zijiang, was an imperial prince and military general of the Jin dynasty of China. He previously served in the state of Cao Wei during the Three Kingdoms period. His grandson, Sima Rui, was the founding emperor of the Eastern Jin dynasty. Life in Cao Wei Sima Zhou was born to Sima Yi and his concubine Lady Fu (伏氏); he was Lady Fu's second son. He had three full brothers: Sima Liang, Sima Jing (司馬京) and Sima Jun (司馬駿). He started his career as a military officer in the state of Cao Wei during the Three Kingdoms period. As a youth, he already had a reputation for his talent and also because of his family background; the Sima family had been the de facto rulers of Wei since 249. Sima Zhou was first appointed as Ningshuo General (寧朔將軍) and put in charge of the security of the Wei nobles living in Ye city. Sometime during the Zhengshi era (240–249) of Cao Fang's reign, he was enfeoffed as the Marquis of Nan'an Village (南安亭侯). Later, he was promoted to a Regular Mounted Attendant (散騎常侍) and elevated from a village marquis to a district marquis under the title "Marquis of Dongwu District" (東武鄉侯). In 260, the Wei emperor Cao Mao attempted to seize back power from the Sima family by staging a coup d'état against the regent Sima Zhao (Sima Zhou's half-brother). Sima Zhou, then holding the position of a Colonel of the Garrison Cavalry (屯騎校尉), led his troops to stop Cao Mao. However, his men dispersed in fear when Cao Mao shouted at them. Cao Mao eventually met his end at the hands of Cheng Ji (成濟), a subordinate of Sima Zhao's adviser Jia Chong. In 263, during the reign of Cao Huan, Sima Zhou was appointed as General of the Right (右將軍) and Inspector (刺史) of Yan Province. A year later, after Sima Zhao restored the five-rank nobility system, which had previously been abolished, Sima Zhou was enfeoffed as the Count of Nanpi (南皮伯). He was also reassigned to be General Who Attacks Barbarians (征虜將軍) and granted imperial authority. Life under the Jin dynasty On 8 February 266, a few months after Sima Zhao's death, his son Sima Yan (Emperor Wu) usurped the throne from Cao Huan and established the Jin dynasty (266–420) to replace the Cao Wei state, with himself as