Wang Chengzong
In 809, Wang Shizhen died, and Emperor Xianzhong initially refused to follow Emperor Dezong's precedent and allow Wang Shizhen's son Wang Chengzong to succeed as military governor of Chengde, until he extracted from Wang Chengzong a promise to surrender two of Chengde's prefectures to imperial control. Wang Chengzong soon reneged on the promise, however, and Emperor Xianzong ordered a campaign against Chengde. Liu Ji's emissary to Weibo Circuit (魏博, headquartered in modern Handan, Hebei), Tan Zhong (), was able to persuade Weibo's military governor Tian Ji'an not to join Chengde's cause, and then persuaded Liu Ji himself to attack Chengde — pointing out that if he did not, Emperor Xianzong would believe that he was complicit in Wang Chengzong's resistance. In spring 810, Liu Ji thus launched his own campaign against Chengde, capturing a number of towns. Emperor Xianzong gave him the honorary chancellor title of "Zhongshu Ling" ().