…Lulong (headquartered in modern Beijing, governed by Zhang Zhongwu — would side with Zhaoyi.

Emperor Wuzong had secured their cooperation by effectively promising the three circuits that he would not interfere with their independence, and had in fact secured the military cooperation of both Weibo and Chengde in the campaign against Zhaoyi by leaving the task of capturing Zhaoyi's three eastern prefectures, east of the Taihang Mountains, to Wang and He Hongjing.

The other imperial generals, including Wang Zai, Shi Xiong, and Liu Mian, concentrate on Zhaoyi's two western prefectures, including its capital Lu Prefecture.

Initially, the imperial forces make no headway against Zhaoyi forces, and the campaign is complicated by a mutiny of the officer Yang Bian at Hedong Circuit (headquartered in modern Taiyuan, Shanxi) early in 844.

Yang's mutiny is quickly put down, however, and …