At the time that Emperor Muzong took the throne, he inherited a state that had just recently been, during his father's reign (which was known as the Yuanhe Restoration (), due to Emperor Xianzong's era name's being "Yuanhe"), restored to unity under the imperial government after various circuits, the most defiant of which were Pinglu (平盧, headquartered in modern Tai'an, Shandong), Weibo (魏博, headquartered in modern Handan, Hebei), Chengde (成德, headquartered in modern Shijiazhuang, Hebei), and Lulong (盧龍, headquartered in modern Beijing), had been effectively independent from the imperial government. As of 819, when Emperor Xianzong's forces crushed those of Li Shidao, the military governor of Pinglu, in effect, these circuits that had broken away from the imperial government since the end of the Anshi Rebellion had resubmitted to the imperial government.