In 193, Cao Cao's father Cao Song was travelling through Xu Province to join Cao Cao in Yan Province. Tao Qian's subordinate, Zhang Kai (), attacked the baggage train, killing Cao Song and escaping with the loot. The death of Cao Song prompted Cao Cao, then the Governor of Yan province, to lead an army to invade Xu Province and massacre countless civilians – ostensibly to avenge his father. Tao Qian requested aid from his allies in Qing Province, and was joined by Tian Kai and his subordinate Liu Bei, and with the reinforcements Tao Qian was able to resist Cao Cao. Cao Cao's forces eventually ran out of supplies and had to withdraw back to Yan Province.