Gao Shun
Liu Bei assisted Gongsun Zan against his rival Yuan Shao in 191 and was given the post of magistrate in Pingyuan Commandery. His post didn't last long as Yuan Shao dealt a devastating blow to Gongsun Zan in 192 and Liu Bei was forced to move east to Qi Commandery. When Tao Qian of Xu Province offered him 4,000 troops and a post in Pei Commandery, Liu Bei accepted. Tao Qian died in 194 and Liu Bei succeeded him as Governor of Xu Province. In 196 Yuan Shu invaded from the south and fought Liu Bei for a month at a stalemate. During this time however, Liu Bei had lost Xiapi Commandery due to Zhang Fei killing its Chancellor allowing Lü Bu, who was at the time taking refuge in the province, to attack Liu Bei and forced him to surrender. Having defeated Liu Bei and taken control of Xu Province, Lü Bu drove away Yuan Shu's army. Though he was defeated, Liu Bei still retained Pei Commandery. When Yuan Shu attacked Liu Bei again, Lü Bu prevented his advance out of fear that Yuan Shu would become too powerful. Liu Bei continued to recruit troops until 198 when he intercepted a trade convoy from Lü Bu. Lü Bu's officers Gao Shun and Zhang Liao retaliated, taking Pei Commandery and forcing Liu Bei to flee to Cao Cao. Cao Cao sent an army under Xiahou Dun to assist Liu Bei against Lü Bu. In the autumn their army was defeated by Gao Shun. When Cao Cao joined them in the winter, they successfully laid siege to Lü Bu in Xiapi Commandery and killed him the following year.