Hanzhong Campaign
In August 219, following Liu Bei's victory over Cao Cao in the Hanzhong Campaign in June that year, Guan Yu decided to follow up by attacking Cao Cao's stronghold at Fancheng (樊城; present-day Fancheng District, Xiangyang, Hubei), which was guarded by Cao Ren. Cao Cao ordered Yu Jin to lead reinforcements to help Cao Ren. It was in autumn and there were heavy showers so the Han River flooded and destroyed Yu Jin's reinforcements. Yu Jin himself surrendered to Guan Yu while his subordinate Pang De refused and was executed.