There were still many other minor warlords, and Cao Cao particularly sought to get them to submit to him. In 197, Zhang Xiu surrendered Wancheng to Cao Cao. However, Cao Cao later had an affair with Zhang Xiu's widowed aunt, angering Zhang. Zhang, who learned of Cao Cao's planned assassination on his life, rebelled and launched a surprise attack on Cao Cao at Wancheng. In this battle, Cao Cao's eldest son Cao Ang, nephew Cao Anmin, and bodyguard Dian Wei were killed, and Cao Cao himself narrowly escaped from death. On the advice of Jia Xu, Zhang Xiu eventually surrendered to Cao Cao in the winter of 199–200. In addition, in 197, Cao Cao was able to persuade Ma Teng and Han Sui, who controlled Yong and Liang provinces (covering most of present-day Shaanxi and Gansu), to submit to him.
