官渡之战
The Battle of Boma or Battle of Baima was the first of a series of battles that led to the decisive Battle of Guandu between the warlords Yuan Shao and Cao Cao in northern China in the late Eastern Han dynasty of China. Although Cao Cao won the battle and Yuan Shao lost his elite general Yan Liang, Cao eventually abandoned his position in Boma to entrench at the strategically important Guandu.