Cao Huan
In 260, after the fourth Wei ruler Cao Mao was killed in a failed coup against the regent Sima Zhao, Cao Yu's son Cao Huan, the Duke of Changdao District (常道鄉公), was chosen to be the new emperor and he ascended the throne shortly after Cao Mao's death. Cao Yu remained as the Prince of Yan when his son was a nominal emperor under Sima Zhao's control. The number of taxable households in his princedom increased throughout the reigns of Cao Rui, Cao Fang, Cao Mao and Cao Huan until it reached 5,500. On 4 February 266, Sima Zhao's son Sima Yan forced Cao Huan to abdicate the throne in his favour, ending the state of Cao Wei and establishing the Jin dynasty. Sima Yan became the emperor and he granted Cao Huan the title "Prince of Chenliu" (陳留王). Cao Yu's status was reduced from that of a prince to a duke, so he became known as the "Duke of Yan" (燕公); he died in 278.