Jia Xu

Jia Xu was an advisor who first served under the corrupt governor Dong Zhuo, and eventually went on to serve Cao Cao.

Early Career
Jia Xu first joined the Imperial court as the "Chief Commandant of Pingjin", when Dong Zhuo first entered Luo Yang. After witnessing his cruel behavior, Jia Xu left the Imperial court. When Dong Zhuo and his clan was exterminated, a handful of his loyalists ― Guo Si, Fan Chou, and Li Jue were able to escape. Wenhe fled the capital with them, building an army through their travels to get to Changan. Li Jue succeeded and led the attack on the city. Jue, Guo Si, Fan Chou wished to make Jia Xu an official nobleman, but he firmly declined. So, instead, they made him the head of a department in charge of recommending people to office. When his mother died, however, he relinquished his position.

Later, Guo Si and Li Jue went on to fight each other for superiority, so Li Jue invited Jia Xu to become his General. He accepted, and when the Emperor was released, Xu came to be under a man named Dian Wei. This was only for a short time, however, as Dian Wei and his army, though respecting Jia Xu, feared that he would turn traitor against them. Jia Xu was courteous however, and soon left them as Zhang Xiu, whom Xu had connections with, sent for him.

Under Zhang Xiu and Wei
Zhang Xiu made good with Jia Xu, who proved his useful intelligence. On one occasion, during Cao Cao's campaign against Zhang Xiu, Jia Xu disagreed with his lord's decision to personally pursue Cao Cao, sure that they would lose. They did, but, when when the lord retreated back, Jia Xu told them to pursue them once again as they would win ― Which they did.

During the time of the Battle of Guan Du, the major warlord Yuan Shao had sent a messenger to request an alliance from Zhang Xiu. Jia Xu told the messenger, "Return and express to Yuan Benchu that we decline. If he could not accept even his brother, could he accept the talented men of the realm?" Jia Xu referred to Yuan Shao's distust for his half-brother, Yuan Shu. Zhang Xiu asked his advisor where they would find refuge, to which he replied they would find it with Cao Cao, as he is weak but controls the Emperor, and with his small numers, would be glad to take them in. Yuan Shao had a very large army, so he would not regard their presence highly. Zhang Xiu thought, and led his troops to Cao Cao. When Cao Cao saw them coming, he rejoiced, and praised Jia Xu. Later in the battle, Jia Xu skillfully advised Cao Cao to many small victories.

Later, when Cao Cao was leading a campaign against Han Sui and Ma Chao, he followed all of Jia Xu's strategies which led to victory and victory.

Jia Xu was an important supporter to Cao Pi's rise to the throne, and the generals in Cao Cao's army would go to him for guidance out of respect.