Lü Bu
In 197, Yuan Shu declared himself emperor and sent his subordinate Han Yin () to meet Lü Bu, proposing a marriage between his son and Lü Bu's daughter, so as to foster a stronger alliance between him and Lü Bu. Lü Bu initially agreed to the proposal and sent his daughter to follow Han Yin back. However, Lü Bu still bore a grudge against Yuan Shu for attacking him five years before, so he changed his mind after listening to Chen Gui. Lü Bu pursued the convoy and retrieved his daughter, captured Han Yin, and sent him to Xuchang, where Han was executed on Cao Cao's order. Cao Cao appointed Lü Bu as General of the Left () and personally wrote him a letter to console him. Lü Bu sent Chen Deng to meet Cao Cao and thank Cao on his behalf. When Chen Deng met Cao Cao, he said that Lü Bu was bold but not very astute, and was untrustworthy, so he should to be eliminated as soon as possible. Cao Cao agreed with Chen Deng's view. Chen Deng was appointed Administrator of Guangling and secretly implanted by Cao Cao as a spy in Lü Bu's forces.