Yuan Shao
In 199, Gongsun Zan was defeated by Yuan Shao at the Battle of Yijing and he committed suicide by setting himself on fire. Gongsun Zan's territories, which extended to the northern boundaries of the Han dynasty's empire, were completely annexed by Yuan Shao. Yuan Shao then turned his attention south towards Cao Cao, who was an emerging power in central China. Yuan allied with Liu Biao and was intent on attacking Cao Cao.