Wang Xingyu
In 886, Emperor Xizong, who had returned to Chang'an after Huang's defeat, was again forced to flee Chang'an, to Xingyuan (興元, in modern Hanzhong, Shaanxi) after his trusted eunuch advisor Tian Lingzi got into a confrontation with the warlords Wang Chongrong the military governor of Huguo Circuit (護國, headquartered in modern Yuncheng, Shanxi) and Li Keyong the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi) and was subsequently defeated by Wang Chongrong and Li Keyong. Two other warlords, Zhu Mei the military governor of Jingnan Circuit (靜難, headquartered in modern Xianyang) and Li Changfu the military governor of Fengxiang, who had previously been allied with Tian, turned against Emperor Xizong as well and supported his distant relative Li Yun the Prince of Xiang as a rival emperor at Chang'an. Zhu subsequently sent his general Wang Xingyu to advance on Xingyuan to try to capture Emperor Xizong, and Wang Xingyu initially defeated the imperial guard general Yang Sheng (). In response, Emperor Xizong sent Song, Li Chan (), and Chen Pei () to station themselves at Mount Datang (大唐峰, in modern Hanzhong) to defend against Wang Xingyu. Wang Xingyu was unable to advance and later, after enticement by Tian's successor and the leading eunuch Yang Fugong, turned against Zhu and killed him. Li Yun fled to Wang Chongrong's territory but was killed by Wang Chongrong. For Song's accomplishments, Emperor Xizong bestowed the imperial surname of Li on him and gave him a new personal name of Maozhen ("prosperous and faithful") as well as a courtesy name of Zhengchen ("rightful subject"). In spring 887, Emperor Xizong made him the military governor of Wuding Circuit (武定, headquartered in modern Hanzhong).