Sima Yi - Service Under Cao Cao

Service Under Cao Cao

Accounts on how Sima joined the service of Cao differ, but he accepted his first position in Cao's camp at the age of 30. According to the Book of Jin, Sima believed that the Han Dynasty would soon come to an end, and felt no motivation to join Cao, which had already taken control of the Han seat of government. He refused Cao's requests to serve, saying that he was suffering from a disease. Cao did not believe Sima's excuse, and sent agents to check on him at night. Sima, knowing this in advance, stayed in bed all night and did not move. In 208, Cao became Imperial Chancellor and ordered Sima to serve him, saying "If he dallies, arrest him." Afraid of what would befall him, Sima finally accepted the position of Wenxueyuan (文学掾). However, according to Weilüe, Cao Hong, Cao Cao's younger cousin, requested the presence of Sima in order to start a friendship with the latter, who did not have a very high opinion of Cao Hong and feigned illness by carrying a cane in order to avoid meeting him. Cao Hong went to Cao Cao in anger and told him what had happened, after which Cao Cao directly requested the presence of Sima. Only then did Sima officially enter Cao Cao's service.

In the Chancellor's service, he rose through the ranks of Dongcaoyuan (東曹掾; in charge of bringing officials into service), Zhubo (主簿; an administrative position), and Sima (司馬; position in charge of aids and advisors). In 215, when Cao Cao defeated Zhang Lu and forced him to surrender, Sima advised that Cao Cao continue to advance south into Yi Province, since Liu Bei had still not stabilized his control of that area. However, Cao Cao did not listen to his advice. Sima was among other advisors who urged for the implementation of the tuntian system and for Cao Cao to take the position of Prince of Wei.