程昱
However, without the assistance from Gongsun Zan's elite cavalry, Liu Dai was soon killed by the Yellow Turbans, and Cao Cao came forth to take over the province. Upon his arrival, Cao Cao sent Cheng Yu a letter concerning his presence in the government. Cheng Yu replied to Cao Cao that he accepted the offer right away, so the commoners asked Cheng Yu: "How can you change your attitude so snobbishly?" Cheng Yu laughed at them without comment. When Cheng Yu joined Cao Cao, he was only assigned as a prefect, a position far lower than the ones Liu Dai offered him in the past. Still, Cheng Yu was determined to follow Cao Cao, as evidenced by his defences against the warlord Lü Bu, who attacked Cao Cao's base while the latter was away on a campaign in Xu Province.