Cao Cao Unification of the North

After Yuan Shao was defeated in Guandu (200 AD), Cao Cao held absolute superiority over him. He died a year later, and his sons fought for control.

His eldest son, Yuan Tan, and his younger son, Yuan Shang, were fighting against each other. Eventually, Yuan Tan surrendered to Cao Cao in order to subdue Yuan Shang. Under Cao Cao, Yuan Shao\'s capital, Ye, fell and Yuan Shang fled to Gongsun Zan who, fearing an attack from Cao Cao killed him and his other brother, Yuan Yao.

Yuan Tan then started a rebellion, but failed and got executed. Gongsun Zan later surrendered to Cao Cao. Thus, the reunification of the North was complete.