Wang Chengzong
In 810, Liu Ji was commanding his Lulong troops in attacking Wang Chengzong, the ruler of neighboring Chengde Circuit (成德, headquartered in modern Shijiazhuang, Hebei), whom Emperor Xianzong had declared a renegade. He had Liu Gun remain at Lulong's capital You Prefecture () to serve as acting military governor, while Liu Zong accompanied him on the campaign, serving as the army commander. During the campaign against Wang, Liu Ji had Liu Zong command the siege of Anping (安平, in modern Hengshui, Hebei), and Anping fell in one day. However, the Lulong army became bogged down at Raoyang (饒陽, in modern Hengshui) and was not able to advance further.