The siege of Suiyang () was a military campaign during the An Lushan Rebellion, launched by the rebel Yan army to capture the city of Suiyang from the loyalist forces of the Tang army. Although the battle was ultimately won by the Yan army, it suffered a major loss of manpower and time. The battle was noted for the Tang army's determination to fight to the last man, as well as the large-scale cannibalism that occurred during the siege.
Background
The An Lushan Rebellion started in December 755. By the end of 756, the rebel Yan army had captured most of northern China, which then included both Tang capitals, Chang'an and Luoyang, and was home to the majority of the empire's population. The Yangtze River basin had thus become the main base of the Tang dynasty's war efforts. In January 757, the newly self-proclaimed Yan emperor An Qingxu ordered general () to join forces with general Yang Chaozong () and besiege Suiyang (present-day Shangqiu, Henan). Suiyang was a city on the Tang-era course of the Grand Canal, sitting midway between the major cities Kaifeng and Xuzhou. The city therefore formed a major obstacle for the rebels on the route from the capitals to the southeastern coast, the breadbasket of the Tang dynasty.
The administrator of Suiyang Prefecture at the time, (), requested help from garrisons in neighboring cities. At the time, Zhang Xun, formerly a county magistrate serving in the Tang government, was the leader of volunteer defenders in Yongqiu. The Tang had granted him the title deputy jiedushi of Henan, but was unable to provide any reinforcement or logistic support. Zhang had held off a rebel siege on his city in the previous year. However, as cities in the area fell one by one, Zhang quickly realized that his position in Yongqiu was becoming untenable. Recognizing the strategic importance of Suiyang, he led 3,000 men to aid its defence. Once he arrived, Zhang Xun took over the military leadership of Suiyang. (), the county magistrate of Chengfu, also arrived to help lead the defence of Suiyang. Meanwhile, Yin Ziqi mustered an army of 130,000 and started besieging the city in late January.
Timeline
The united army of Zhang Xun and Xu Yuan, around 6,800 men, prepared to defend Suiyang with their lives. Xu Yuan focused on supplies management and after-battle repairs. Zhang Xun, on the other hand, focused on battle tactics.
Despite daily sieges by the Yan army, the Tang soldiers never let up. Zhang Xun's troops played the battle drums during the night, acting as if they were going to fight. Consequently, the Yan army were forced to stand on guard during the night, and suffered from lack of sleep. Eventually, some troops did not bother to put on their armor when they heard these battle drums, and kept sleeping. After the Yan army lowered their defenses, Zhang Xun sent a dozen generals, including the famed archer () and (), to lead 50 cavalry each in an attack on the enemy camp. The ambush was successful and 5,000 Yan troops were slaughtered.
Zhang Xun had long wanted to give Yan morale a major blow, and the best way to do this would be to hurt or kill the Yan general Yin Ziqi. However, Zhang Xun did not know what Yin Ziqi looked like, not to mention he would be in a mix of soldiers. Zhang Xun therefore turned to psychology. He ordered his troops to shoot weeds, instead of arrows, at a few enemy soldiers. When these soldiers noticed that they were being shot by weeds and left unharmed, they were overjoyed. They promptly ran to Yin Ziqi to report that the Tang army had already run out of arrows. Zhang Xun noticed where the soldiers ran and ordered his best archer, Nan Jiyun, to shoot at Yin Ziqi. One such arrow hit Yin Ziqi in his left eye, throwing the Yan army instantly into chaos. The siege ended with the expected major blow to Yan morale.
After 16 days of siege and ambush, the Yan army had already lost 20,000 men. Yin Ziqi decided that his army was too tired to fight, so he ordered a temporary retreat to regroup. Yin Ziqi returned to besiege Suiyang two months later, with an additional 20,000 fresh troops.
Originally, Xu Yuan had prepared for the upcoming battle by storing a year's worth of food inside of Suiyang. But the district governor had insisted that he share the large food supply with other nearby fortresses, and hence the food supply became much less than what Xu Yuan originally planned. By July, the Tang soldiers had fallen into a serious food shortage. Tang soldiers were given very small daily rations of rice. If they wanted more food, they would need to settle for whatever animals, insects, and tree roots that could be found in their vicinity.