Plot: Yuan Shao, with hundreds of thousands of troops, occupied the states and counties north of the Yellow River, such as You, Ji, Qing, and He, and was in a favorable position to attack and retreat to defend. Cao Cao occupied the states and counties south of the Yellow River, such as Gun, Yu and Xu, and received Emperor Xian of Han in Xuchang to "hold the Son of Heaven and make the vassals"