Наньян
In 197, Yu Jin accompanied Cao Cao on a campaign against the warlord Zhang Xiu in Wancheng (宛城; present-day Wancheng District, Nanyang, Henan). Zhang Xiu initially surrendered and pledged allegiance to Cao Cao, but rebelled later and defeated Cao Cao in a surprise attack. There was chaos and disorder in Cao Cao's forces as they retreated to Wuyin County (舞陰縣; southeast of present-day Sheqi County, Henan).