# Cao Zhi (Yungong)

Cao Zhi (Chinese: 曹志; died 288), courtesy name Yungong (允恭), posthumously known as Duke Ding of Juancheng (鄄城定公), was a son of Cao Zhi, Prince Si of Chen, and his unnamed concubine, and a grandson of Cao Cao. Besides his heritage, Cao Zhi was best known for his friendship with Sima Yan (Emperor Wu of Jin), and his support of Sima You remaining in the capital to help in the administration of the empire, against Yan's wishes.

## Background and life under Cao Wei

Cao Zhi was born in an unknown year to Cao Zijian and his unnamed concubine. At a young age, Zhi was studious and well known for his literary talents; he was also skilled in riding and archery. His father made him heir and praised him, "This shall be the protector of our clan." At some point, the Wei court granted Zhi the title of Duke of Mu Village (穆乡公), and his brother Cao Miao (曹苗) Duke of Gaoyang Village (高阳乡公); Cao Zijian wrote a memorial to thank the imperial court for the grants.
When Cao Zijian died in December 232, Cao Zhi inherited his peerage as Prince of Chen; he was later appointed Prince of Jibei. During the Jingchu era (237–239) of Cao Rui's reign, Cao Zijian was posthumously rehabilitated, and his literary works were allowed to be compiled and stored. Cao Zhi's fiefdom was also expanded to 990 households.
Despite his father's hopes, historical records did not indicate Cao Zhi's involvement in protecting the Cao clan from the Sima clan after the death of Cao Rui, the last Cao Wei ruler who wielded real power, in January 239. In February 249, Sima Yi became sole regent of the state of Cao Wei after he overthrew Cao Shuang in a coup. After Yi's death in September 251, his sons Sima Shi and Sima Zhao also became regents of Cao Wei.
In June 260, after Sima Zhao's regicide of Cao Mao, Zhao's son Sima Yan was ordered to receive the new emperor Cao Huang at Yecheng. Cao Zhi went to visit Sima Yan at night; the two's conversations lasted until the next morning, and Sima Yan was deeply impressed by Cao Zhi.
Less than six years after their meeting, on 4 February 266, Sima Yan forced Cao Huan (Cao Huang after changing his name) to abdicate. Five days later, Cao Huan was appointed Prince of Chenliu, while the former princes of Cao Wei were demoted to marquesses.

## During Emperor Wu's reign

As Duke of Juancheng, Cao Zhi held several positions, including stints as administrator at Leping, Zhangwu and Zhao Commanderies.
Cao Zhi was once asked by Sima Yan if the treatise "Liu Dai Lun" (六代论) was authored by his father. Zhi replied that the bibliography of his father's works should be consulted. When the treatise was not listed in the bibliography, Sima Yan asked about the author's identity; Zhi replied that the actual author was his clan elder Cao Jiong (曹冏), who attributed the treatise to Zijian due to the latter's fame. Sima Yan then declared the authorship matter closed.
In February or March 283, Sima Yan ordered the court to discuss about ordering his brother Sima You, the Prince of Qi, to leave the capital Luoyang for his fiefdom. Many officials, including Cao Zhi, opposed the motion. In particular, probably due to his father's rejection by Cao Rui, Cao Zhi was vehement in his opposition. When Sima Yan read Cao Zhi's memorial, he exclaimed in anger, "If even Cao Zhi could not understand my intentions, what more the others from across the Four Seas?" He then ordered the officials who had voiced their opposition to be put on trial. However, for Cao Zhi, he was merely relieved of his posts and sent back to his residence.
Soon after being sent back to his residence, Cao Zhi's mother died. In his mourning and grief, Cao Zhi became ill and unpredictable in his emotions. After his death in 288, there were discussions about giving him an unflattering posthumous name. An official named Cui Bao (崔褒), citing the story of Wei Ke (魏颗), opposed the motion. Eventually, Cao Zhi's posthumous name became "Ding".