In fall 623, the Tang general
Fu Gongshi, who had served as the deputy of the powerful general
Li Fuwei the Prince of Wu as the military governor of the lower Yangtze region, rebelled against Tang rule while Li Fuwei was at Chang'an, declaring himself the Emperor of Song. Emperor Gaozu commissioned Li Xiaogong to attack Fu, again making Li Jing, who was then in charge of the modern
Guangdong and
Guangxi region, Li Xiaogong's assistant, and also sending other generals Huang Junhan () and
Li Shiji to attack Fu from other fronts. Before his army was set to depart Xiang Prefecture, Li Xiaogong held a feast, when, for reasons unexplained, Li Xiaogong's cup, filled with water, suddenly appeared to be filled with blood, which was considered an ill omen and causing the generals at the feast to lose heart. However, Li Xiaogong calmly stated: :
Blessings and curses have no firm foundation, and it depends on how you act on them. I will not ignore the signs, and I will not make you gentlemen worry. Fu Gongshi is full of treachery and sins, and I rightfully attack him now in the name and spirit of the emperor. The blood in my cup is sign that this thief will soon lose his head! He drank the blood-water with ease, impressing and calming his generals. He then sailed down the Yangtze, attacking and defeating the Song generals at multiple battles. Fu ordered his generals Feng Huiliang () and Chen Dangshi () to take up position at Mount Bowang (, in modern
Ma'anshan,
Anhui), preparing for the assault, instructing Feng and Chen not to engage Li Xiaogong, but to wear him down. However, Li Xiaogong cut off their supply route, and when Feng and Chen's food supplies ran low, they challenged Li Xiaogong. Against suggestions by some officers that he bypass Feng and Chen and attack the Song capital Danyang (, in modern
Nanjing,
Jiangsu) directly, Li Xiaogong, perhaps with Li Jing's suggestion, confronted Feng and Chen, initially using the weaker segment of his forces to battle Feng and Chen and, after initial losses, draw Feng and Chen in deeper, and then attacked them, defeating them decisively, with the aid of Li Fuwei's subordinate general Kan Leng (). After the victory, Li Xiaogong and Li Jing attacked Danyang. Fu, in fear, abandoned Danyang and fled east to
Kuaiji, but was captured by the local men in Chang prefecture (roughly modern
Changzhou, Jiangsu) and delivered to Danyang. == Later life ==