Jia Xu (147 – 11 August 223),[a] courtesy name Wenhe, was an official of the state of Cao Wei during the early Three Kingdoms period of China.

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 May 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.

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.

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.

However, Cao Pi ignored his advice and invaded Wu, but ended up sustaining heavy losses and not making any significant gains.

[Sanguozhi 3] Jia Xu was nominated as a xiaolian to serve in the Eastern Han government as a Gentleman Cadet (郎).

As Duan Jiong had served for years as a general guarding the Han Empire's western regions, he was well known among the people living in the area.

He was promoted to Colonel Who Attacks Barbarians (討虜校尉) and assigned to the unit led by Dong Zhuo's son-in-law, Niu Fu.

[Sanguozhi 5] In 192,[3] Dong Zhuo was assassinated by Lü Bu in the imperial capital, Chang'an,[b] while Niu Fu was murdered by his subordinates.

[3] The rest of Dong Zhuo's loyalists, including Li Jue, Guo Si and Zhang Ji, became fearful and wanted to disband and return to their respective home commanderies.

He argued that Dong Zhuo's death marked the end of his tyranny and a possible revival of the declining Eastern Han dynasty.

[Sanguozhi zhu 2] When there were tensions between Li Jue, Guo Si and Fan Chou, with their respective subordinates urging them to go to war, Jia Xu reprimanded them for their behaviour and tried to persuade them to avoid conflict.

"[Sanguozhi zhu 4] Li Jue used material wealth to tempt thousands of Qiang tribesmen to support him in his struggle against Guo Si.

Jia Xu secretly hosted a banquet for the tribal chiefs, gave them some expensive material gifts, and succeeded in making them leave.

[Sanguozhi zhu 5] Jia Xu played an important role in resolving the conflict between Li Jue and Guo Si, and in ensuring Emperor Xian's safety during the time.

He hated certain officials such as Zhao Wen (趙溫), Wang Wei (王偉), Zhou Zhong (周忠) and Rong Shao (榮邵), and wanted to execute them.

"[Sanguozhi 11] Jia Xu left Duan Wei and headed to Nanyang Commandery, where Zhang Xiu welcomed him and treated him like a family elder.

[5] Zhang Xiu wanted to seize the opportunity to launch a counterattack, but Jia Xu warned him not to and predicted that he would be lose the battle.

If you follow in the footsteps of the Chu state by attracting talents to serve in the government and by improving the lives of the people, you won't need to resort to force to subdue the Jiangdong territories.

Jia Xu replied: "I hope you will behave in a virtuous and humble manner, perform your duties faithfully, and be a filial son.

[Sanguozhi 23] On 6 April 220, while Cao Pi was still King of Wei, Jia Xu was appointed as Grand Commandant (太尉).

[Sanguozhi 24] In late 220, Cao Pi forced Emperor Xian to abdicate the throne to him, thus ending the Han dynasty.

[Sanguozhi 25] Jia Xu's promotion was allegedly an expression of gratitude from Cao Pi, who wanted to thank him for helping him seize the succession years ago.

[Sanguozhi zhu 9] Sun Quan laughed when he heard that Cao Pi had appointed Jia Xu as his Grand Commandant.

[Sanguozhi zhu 10] Sometime between 220 and 223, Cao Pi wanted to attack and conquer Wei's two rival states, Wu and Shu.

Liu Bei has talent and great ambition; Zhuge Liang excels in statecraft; Sun Quan understands trends and sees through deception; Lu Yi assesses military power very well.

[Sanguozhi 32] According to the Shiyu (世語), Jia Mo served as a Regular Mounted Attendant (散騎常侍) and General Who Protects the Army (護軍將軍) during the reign of Emperor Hui in the Western Jin dynasty.

[Sanguozhi zhu 12] Jia Xu was first introduced as a playable character in the seventh instalment of Koei's Dynasty Warriors video game series.