Later in 623, the general Fu Gongshi rebelled against Tang at Danyang (, in modern Nanjing, Jiangsu) and declared himself the Emperor of Song. Li Shiji participated in the campaign against Fu, commanded by Emperor Gaozu's distant nephew Li Xiaogong the Prince of Zhao Commandery. After Tang forces converged on Danyang and defeated Song forces at Mount Bowang (, in modern Ma'anshan, Anhui), Fu fled, and Li Shiji chased him down and, after he was captured by the gentlemen in the country, delivered him to Danyang, where Li Xiaogong executed him.