Yuan Shang
In 203, Cao Cao scored a major victory over the Yuans, who retreated to Ji Province's capital, Ye (鄴). Cao Cao then planned to besiege Ye, but later withdrew his forces after heeding Guo Jia's advice. Guo Jia reasoned that if Cao Cao pressured the Yuans, they might unite against a common enemy; however, if Cao Cao retreated, the disgruntled Yuan brothers would start fighting among themselves. Guo Jia's prediction came true later when Yuan Tan, still bearing a grudge against Yuan Shang for receiving a larger inheritance, attacked Yuan Shang, but his forces in Qing Province defected to Yuan Shang. Yuan Tan fled to Pingyuan (in present-day Dezhou, Shandong) and was besieged by Yuan Shang there. Yuan Tan sought help from Cao Cao, and Cao advanced north to attack Ye, forcing Yuan Shang to lift the siege on Pingyuan. In early 204, Yuan Shang incorrectly believed that Cao Cao had withdrawn, so he attacked his brother again at Pingyuan. Cao Cao attacked Ye once more and Yuan Shang headed back to defend his base but was defeated by Cao Cao. Yuan Shang then fled north to Zhongshan (in present-day Shijiazhuang, Hebei), and Ye fell to Cao Cao. Gao Gan also surrendered Bing Province to Cao Cao.