Tian Hongzheng
After Wu Yuanji's execution, Li Shidao and Wang Chengzong both became fearful. In 818, Wang offered to surrender two prefectures to imperial control and send his two sons to Chang'an to serve as hostages. He also sought intercession from Tian Hongzheng. With Tian also requesting that Emperor Xianzong accept his offer, Emperor Xianzong did so, merging the two prefectures that Wang surrendered into neighboring Henghai Circuit (橫海, headquartered in modern Cangzhou, Hebei), which had been obedient to the imperial government. Li Shidao also offered to surrender three of his 12 prefectures to imperial control and send his son as a hostage—but soon reneged on the offer. Emperor Xianzong thus declared a general campaign against his Pinglu Circuit, and soon, the imperial forces were repeatedly dealing defeats to Pinglu troops.