Sometime between 5 February and 6 March 197, Cao Cao led his forces to attack Zhang Xiu. When his forces reached the Yu River (淯水; now known as the Bai River 白河; flowing through parts of present-day Henan and Hubei), Zhang Xiu surrendered without putting up a fight. Cao Cao was so pleased that he threw a banquet for Zhang Xiu and his followers. During the banquet, Dian Wei, a military officer under Cao Cao, stood guard beside his lord and held a giant battle axe whose blade was one "chi" long. Zhang Xiu and his followers did not dare to look up when they toasted to Cao Cao.