at Mamingge (馬鳴閣), Hanzhong's main communication line. Xu Huang led a separate detachment to launch a fierce attack on Chen Shi and defeated him. The casualty rate on Chen Shi's side was very high as many of his soldiers were forced to jump off the cliff during the attack. Cao Cao was delighted when he heard of the victory and he gave orders to Xu Huang: "This pass is a crucial gateway into Hanzhong. Liu Bei intends to isolate the pass and then move on to conquer Hanzhong. You have done well in foiling the enemy's attempt." Cao Cao then personally led reinforcements to Hanzhong Commandery to counter Liu Bei's advances. Battle of Fancheng Xu Huang's most glorious moment in his military career came at the Battle of Fancheng in 219. When Fancheng (樊城; in present-day Xiangyang, Hubei) and Xiangyang were besieged by Liu Bei's general Guan Yu, Cao Cao first sent Yu Jin to lead a relief force to lift the siege but Yu Jin's seven armies were destroyed by a flood. Cao Cao then ordered Xu Huang to lead a second relief force to lift the siege. Cao Ren, the general defending Fancheng, and Lü Chang (呂常), who defended Xiangyang, were both under siege for months. Knowing that most of his soldiers were composed of new recruits without training, Xu Huang did not go straight into battle but camped behind the enemy at Yanglingbei (陽陵陂; northwest of present-day Xiangyang, Hubei) to impose a deterrent effect. In the meantime, Cao Cao sent subordinates Xu Shang (徐商) and Lü Jian (呂建) to assist Xu Huang and instructed Xu Huang to advance only when Xu Shang, Lü Jian and all other reinforcements had arrived. At the time, Guan Yu had set up a camp at Yancheng (偃城; north of present-day Xiangyang, Hubei). When Xu Huang showed up, he ordered his troops to pretend to dig trenches around Yancheng to fool the enemy into thinking that they were trying to cut off the supply routes leading to Yancheng. The enemy fell for his ruse, burnt down their camp and abandoned their position, thus allowing Xu Huang to gain a foothold at Yancheng. After capturing Yancheng, Xu Huang pressed on and set up two linked camps about 30 zhangs away from Guan Yu's encirclement. Before Xu Huang attacked, Cao Cao sent Yin Shu (殷署), Zhu Gai (朱蓋) and other officers to lead another