Wei and several other staff member of Zhang's, and put Zhang under arrest. The next day, the mutineers began to regret their actions, but when they met Zhang to ask for forgiveness, Zhang did not speak at all. The mutineers believed that Zhang was not intending to pardon them, and instead supported Zhu Kerong's father Zhu Hui to serve as the acting military governor. Zhu Hui declined, but recommended Zhu Kerong, and the soldiers agreed. The imperial government reacted to the mutiny by ordering that Zhang be demoted, while transferring Liu Wu the military governor of Zhaoyi Circuit (昭義, headquartered in modern Changzhi, Shanxi) to Lulong. Liu Wu, however, feared Zhu Kerong's strength and did not dare to try to head to Lulong, so Emperor Muzong allowed him to return to Zhaoyi. Mo Prefecture troops soon mutinied as well and allowed Zhu's mutineers to enter Mo Prefecture; shortly thereafter, Ying Prefecture troops also mutinied and seized Lu and the eunuch monitor of the army, sending them to Zhu. Meanwhile, with Wang Tingcou also having mutinied, killed Tian Hongzheng the military governor of neighboring Chengde Circuit (成德, headquartered in modern Shijiazhuang, Hebei), and took over control of Chengde, Zhu and Wang allied and put Chengde's Shen Prefecture (深州, in modern Hengshui, Hebei), whose prefect Niu Yuanyi () had refused to follow Wang, under siege. Zhu also attacked Yiwu Circuit (義武, headquartered in modern Baoding, Hebei)'s Yi Prefecture (易州, in modern Baoding) and Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi)'s Wei Prefecture (蔚州, in modern Zhangjiakou). Emperor Muzong declared a general campaign against both Wang and Zhu, but the imperial armies soon were bogged down, and the imperial treasury could not afford fighting both circuits. In winter 821, the chancellors thus suggested that, as Zhu had spared Zhang and Wang had killed Tian, there was a difference between them and that Zhu should be pardoned. Emperor Muzong agreed, and commissioned Zhu as the military governor of Lulong. After receiving the commission, Zhu released Zhang and Lu to the imperial government. However, Zhu and Wang (who was also pardoned and commissioned shortly after) continued to have Shen Prefecture under siege, and after they captured Gonggao (弓高, in modern Cangzhou) to cut off the supply routes for the imperial troops, the imperial forces and Niu were in desperate straits. When Pei Du the military governor of Hedong sent letters to rebuke them, Zhu