Yan Liang
In 200, after Yan Liang was killed in the Battle of Boma, Yuan Shao brought his main army south of the Yellow River and launched a full-fledged attack on Cao Cao. Wen Chou and Liu Bei were sent forth with a vanguard force of more than 5,000 riders to pursue Cao Cao's retreating forces. Making a stand atop a knoll, Cao Cao retained less than 600 cavalry and let loose the remaining horses.