The Battle of Xiapi (下邳之战) was a siege of the city of Xiapi (下邳, in Xu Province) from 198 into 199. Cao Cao and Liu Bei led the attacking force against Lü Bu, who had seized Xu Province and was based at Xiapi. The siege dragged on until Cao Cao’s forces diverted a river to flood the city, weakening defences and morale. Lü Bu’s subordinates Song Xian and Wei Xu captured Chen Gong and defected; Lü Bu was then taken prisoner. Despite his pleas and Liu Bei’s earlier dealings with him, Cao Cao had Lü Bu and Chen Gong executed. Xu Province passed under Cao Cao’s control. The battle marked the end of Lü Bu as an independent power and is a key episode in both history and the Romance.
Context
Lü Bu had repeatedly shifted allegiances and had seized Xu Province from Liu Bei with Zhang Fei’s guard absent. Cao Cao had already defeated Lü Bu at Puyang and now joined with Liu Bei to finish him. The flooding of Xiapi and the defection of Lü Bu’s officers are often cited as examples of siege warfare and the collapse of loyalty under pressure.