The Battle of Tong Pass, also known as the Battle of Weinan, was fought between the warlord Cao Cao and a coalition of forces from Guanxi (west of Tong Pass) between April and November 211 in the late Eastern Han dynasty of China. The battle was initiated by Cao Cao's western expansion, which triggered uprisings in Guanxi. Cao Cao scored a decisive victory over the Guanxi coalition and established a hold of the Guanzhong region.