Gao Pian
On May 1, 887, Bi and Zheng, after issuing public declarations denouncing Lü, departed Gaoyou and advanced toward Yang Prefecture. Lü oversaw the defense and was initially able to repel Bi's attacks. Bi, who believed that his army was not strong enough to capture Yang Prefecture, sent a letter to Qin Yan, who was then the governor (觀察使, "Guanchashi") of Xuanshe Circuit (宣歙, headquartered in modern Xuancheng, Anhui), offering the military governorship of Huainan to him and asking for aid. Qin sent his officer Qin Chou () to reinforce Bi. Meanwhile, Gao and Lü had a falling out inside the city, and Gao put up a defense at his headquarters, commanded by his nephew Gao Jie (), to guard against Lü. Gao Pian subsequently sent the officer Shi E () to meet with Bi, along with Bi's youngest son. Bi ordered his young son to return to Gao Pian, stating, "If the Chancellor executes Lü Yongzhi and Zhang Shouyi [(張守一, a close association of Lü's and also a sorcerer that Gao trusted)] to show me his intent, I will surely not turn back on his grace, and I am willing to have my wife and children serve as hostages." Gao Pian, worried that Lü might preemptively slaughter Bi's family, put Bi's family under protective custody.