夏侯淵
In 217, Liu Bei led a campaign to attack Hanzhong, which was under the control of Cao Cao. His force met with resistance led by Xiahou Yuan at Yangping Pass (). The confrontation dragged on for more than a year until one night, Liu Bei set fire to the barbed fence around Xiahou Yuan's camp at the foot of Mount Dingjun. Alarmed by the attack, Xiahou Yuan sent Zhang He to defend the eastern corner of the camp, while he guarded the south. Liu Bei's main force pressed against Zhang He, outmatching the latter. Xiahou Yuan had to dispatch a fraction of his own troops to Zhang He's rescue.