Sun Ru (; died July 3, 892), formally the Prince of Le'an (), was a Chinese military general and politician during the Tang Dynasty. He initially served as a general under the pretender emperor Qin Zongquan. After Qin's defeat, he nominally submitted to Tang imperial authority and contended for control of the central-lower Yangtze River region with Yang Xingmi; he was eventually defeated by Yang and executed. His subordinate Ma Yin was the eventual founder of the Five Dynasties and Ten Kingdoms period state Chu.
Background and service under Qin Zongquan
It is not known when Sun Ru was born. His family was from Henan County, one of the two counties making up the Tang Dynasty eastern capital Luoyang. At some point, he became a low-level officer at Zhongwu Circuit (忠武, headquartered in modern Xuchang, Henan), where he befriended fellow officer Liu Jianfeng. Later, during the rebellion by the major agrarian rebel Huang Chao, Sun served under the command of Qin Zongquan.
By 884, Huang had been defeated and killed, but Qin, who then controlled Fengguo Circuit (奉國, headquartered in modern Zhumadian, Henan) as its military governor (Jiedushi), then became a rebel himself against Emperor Xizong of Tang. As of late 884, Qin was sending a number of his officers to attack or seize territory around his. As part of Qin's campaigns, Sun seized Luoyang, Meng Prefecture (孟州, in modern Jiaozuo, Henan), Shan Prefecture (陝州, in modern Sanmenxia, Henan), and Guo Prefecture (虢州, in modern Sanmenxia). In summer 885, however, he was again battling the Tang defender of Luoyang, Li Hanzhi, for control of Luoyang. It was said that while Li initially abandoned Luoyang after running out of food supplies, Sun only occupied Luoyang for about a month, before burning the palaces, government offices, and houses, and leaving Luoyang after plundering it, allowing Li to again occupy Luoyang.
In late 886, Qin sent Sun to capture Zheng Prefecture (鄭州, in modern Zhengzhou, Henan), and Sun did so, forcing the Tang prefect of Zheng, Li Fan (), to flee to Daliang (大梁, in modern Kaifeng, Henan), then under control of the Tang general Zhu Quanzhong. Sun then attacked and seized Heyang (河陽, in modern Luoyang), forcing the acting military governor of Heyang, Zhuge Zhongfang (), to flee to Daliang as well. Sun claimed the title of military governor of Heyang, but Tang generals Zhang Quanyi and Li, in alliance with each other, stationed themselves at Huai Prefecture (懷州, in modern Jiaozuo, Henan) and Ze Prefecture (澤州, in modern Jincheng, Shanxi), respectively, and continued to resist Sun.
In summer 887, Qin gathered his forces and made an attempt to destroy Zhu once and for all, but was defeated by Zhu and his allies Zhu Xuan and Zhu Jin. Upon hearing of Qin's defeat, most of the officers he sent to the various surrounding regions abandoned their posts and fled. Sun also abandoned Heyang, and it was said that he slaughtered its people and burned its houses. Heyang Circuit came under the joint control of Li and Zhang.
Seizure of Yang Prefecture
In fall 887, with Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu) recently thrown into a state of confusion and war due to internecine battles between the military governor Gao Pian and Gao's officers Lü Yongzhi, Qin Yan, Yang Xingmi, and Bi Shiduo, among others, which resulted in a Yang Xingmi victory but the capital Yang Prefecture () and surrounding regions being laid waste, Qin Zongquan sent his brother Qin Zongheng () and Sun Ru southeast to try to wrest the control of Huainan from Yang Xingmi. (Serving under them were, among others, Liu Jianfeng, Zhang Ji (), Ma Yin, and Qin Zongquan's cousin Qin Yanhui (). They quickly advanced on Yang Prefecture and seized the food supplies that Yang Xingmi had brought to Yang Prefecture during his recent siege against Qin Yan and Bi, and they put Yang Prefecture under siege. However, with Qin Zongquan recently having been defeated by Zhu Quanzhong, Qin Zongheng was ordered by Qin Zongquan to return to Cai Prefecture to aid Qin Zongquan and tried to do so. Sun, believing that Qin Zongquan was nearing defeat, refused to do so. Upon further orders by Qin Zongheng to prepare to do so, Sun killed him and took over the army. Qin Zongheng's officer An Renyi (), instead of submitting to Sun, surrendered to Yang Xingmi.