In 215, Cao Cao attacked Zhang Lu and defeated him at the Battle of Yangping. Zhang Lu surrendered and his domain in Hanzhong came under Cao Cao's control (January 216). Against the advice of his followers to move south and attack Liu Bei in Yi Province, Cao Cao withdrew his armies and left Xiahou Yuan in command of a small force to defend Hanzhong. The following year, Cao Cao pressured Emperor Xian into granting him a title of nobility, "King of Wei". Over the next few years, Cao Cao's style of living became more like the emperor's, and he also received greater honours.