Tian Chengsi
In spring 781, Li Baochen died, and Emperor Dezong rejected the request by Li Baochen's son Li Weiyue to succeed his father as the military governor of Chengde Circuit (成德, headquartered in modern Shijiazhuang, Hebei). As per the alliance agreement, Li Zhengji and Tian Chengsi's nephew Tian Yue, who had succeeded Tian Chengsi in 779 with imperial approval, prepared for war against the imperial troops, using as an excuse that the chancellor Liu Yan had recently been killed due to false accusations by fellow chancellor Yang Yan. As part of his preparation, Li Zhengji unsuccessfully tried to stop the food shipments from the Yangtze River region, through the Grand Canal, to the Tang capital Chang'an, as the imperial general Zhang Wanfu () was able to escort the food shipments through despite intimidation by Pinglu troops.