 Tian further cemented the relationship with Li Na by sending Sun to Pinglu's headquarters at Yun Prefecture (), announcing an imperial edict (which Tian Xu had forged) declaring Di Prefecture to be part of Pinglu Circuit.In anger, Wang sent his son Wang Shiqing () to attack Weibo's Bei Prefecture (貝州, in modern Xingtai, Hebei), occupying four counties of Bei Prefecture.In winter 790, Emperor Dezong, wanting to put an end to the campaigns between these circuits, ordered Li Na to return Di Prefecture to Chengde; Li Na demanded that Wang return the four counties of Bei Prefecture to Weibo first.