李孝恭
Once Li Fuwei left Danyang, Zuo persuaded Fu into planning a rebellion. However, Wang had actual command of the army, and therefore, Fu decided to trick Wang by claiming that Li Fuwei was doubting Wang's loyalty. Wang, angry over the revelation, gave up command of the army, and Fu took control and then tried to persuade Wang to join his plot. Wang, realizing that he had been tricked, nevertheless refused to join Fu, so Fu strangled him. In fall 623, Fu, claiming that Li Fuwei had been detained by Emperor Gaozu and had ordered him to rebel, did so. He soon declared himself the Emperor of Song, and he was able to get another rebel leader who had submitted to Tang as well, Zhang Shan'an (), who controlled the modern northern Jiangxi and eastern Hubei region, to submit to him. Emperor Gaozu sent his generals Li Xiaogong the Prince of Zhao Commandery (the son of his cousin), Li Jing, Huang Junhan (), and Li Shiji against Fu, with Li Xiaogong in overall command. In winter 623, Zhang was captured by the Tang general Li Daliang, cutting off a flank support for Fu.