He quickly captured De Prefecture, and with Henghai's capital Cang Prefecture (滄州) under attack by a general under imperial orders, Li Zaiyi the military governor of Lulong Circuit (盧龍, headquartered in modern Beijing), the De Prefecture soldiers fled to Zhen Prefecture (鎮州, in modern Shijiazhuang, Hebei), the headquarters of Li Tongjie's ally Wang Tingcou the military governor of Chengde Circuit (成德).
Li You (李祐) (died 829), spelled "Li Yu" in the Wade-Giles system, Chinese general of the Tang Dynasty