Jia Xu, Chinese politician (b. 147)
Jia Xu (147 – 11 August 223), courtesy name Wenhe, was an official of the state of Cao Wei during the early Three Kingdoms period of China. He started his career in the late Eastern Han dynasty as a minor official. In 189, when the warlord Dong Zhuo took control of the Han central government, he assigned Jia Xu to the unit led by Niu Fu, his son-in-law. In 192, after Dong Zhuo was assassinated by Lü Bu, Jia Xu advised Li Jue, Guo Si and Dong Zhuo's loyalists to fight back and seize control of the imperial capital, Chang'an, from a new central government headed by Lü Bu and Wang Yun. After Li Jue and the others defeated Lü Bu and occupied Chang'an, Jia Xu served under the central government led by them. During this time, he ensured the safety of the figurehead Han emperor, Emperor Xian, who was being held hostage by Li Jue. He also attempted to prevent internal conflict between Li Jue and Guo Si, but with limited success. After Emperor Xian escaped from Chang'an, Jia Xu left Li Jue and briefly joined the general Duan Wei before becoming a strategist of the warlord Zhang Xiu. While serving under Zhang Xiu, he advised his lord on how to counter invasions by the warlord Cao Cao, who had received Emperor Xian in 196 and taken control of the central government. In 200, during the Battle of Guandu between Cao Cao and his rival Yuan Shao, Jia Xu urged Zhang Xiu to reject Yuan Shao's offer to form an alliance and instead surrender to Cao Cao. Zhang Xiu heeded his advice. Jia Xu then became one of Cao Cao's strategists.

During his service under Cao Cao, Jia Xu made three important contributions. First, during the Battle of Guandu, he urged Cao Cao to switch from being on the defensive to adopting an offensive stance, which ultimately led to Cao Cao's decisive victory over Yuan Shao. Second, during the Battle of Tong Pass in 211, he suggested to Cao Cao to pretend to agree to make peace with the northwestern warlords Han Sui and Ma Chao, and then sow discord between them. Cao Cao heeded his suggestion, successfully stirred up internal conflict among the warlords, and then used the opportunity to defeat them. Thirdly, in the 210s, when Cao Cao's sons Cao Pi and Cao Zhi were fighting to be their father's successor, Jia Xu indirectly helped Cao Pi by giving him advice and hinting to Cao Cao that he should choose the older son to be his heir apparent. After Cao Cao's death in 220, Cao Pi ended the Eastern Han dynasty by forcing Emperor Xian to abdicate the throne to him, and founded the state of Cao Wei with himself as the emperor. As an expression of gratitude to Jia Xu, Cao Pi appointed him as Grand Commandant – one of the top three positions in the Wei government – and promoted him to a district marquis. Between 220 and 223, Jia Xu advised Cao Pi against attacking Cao Wei's rival states, Eastern Wu and Shu Han, and focus on internal development. However, Cao Pi ignored his advice and invaded Wu, but ended up sustaining heavy losses and not making any significant gains. Jia Xu died in 223.