seat of Xuzhou until it was eliminated in the early Ming. The raging wars inflicted upon Xuzhou until the Emperor Taizong of Tang's enthronement in 626. Keeping the northern rebellions and warfare a distance gave Xuzhou scope for developing during the most period of the Tang dynasty. According to the Old Book of Tang and the New book of Tang, in 639, the total population of Pengcheng County, Fei County and Pei County was only 21,768, versus 205,286 in 742. In 781, Li Na marched south to besiege Xuzhou. Although his revolt was quell soon, the halt of the transport by the Bian Canal impelled the court to secure the area. The then prefect of Xuzhou, Zhang Jianfeng was designated as the first military governor of Xuzhou–Sizhou–Haozhou () which was headquartered in Xuzhou since 788. The title was restored and renamed Wuning () in 805, after an interval of five years. Wang Zhixing, another military governor of Wuning, established several battalions (the most notorious one among is the Silver Sword) in the Army specifically for select recruits. These soldiers not only defy military discipline but also show defiant towards the successors to Wang. In 832, Li Ting received a threatening letter prior to his induction in there, made him resigned immediately. Then Wuning suffered mutinies in 849, 859 and again in 862. Another two governors were expelled. Wang Shi was appointed, under the circumstances. He put the mutiny down by executing part of the garrison troops and disbanded the rest, which became thugs and loot later. In 864, the court declared an amnesty in the area, and promised that all thugs who willingly re-enrolled would be sent for a tour of duty in the southern, and then, presumably, returned to regular army service in the north. Three thousand men surrendered and were sent to the south to join the two thousand former Wuning soldiers there. The breached pledge irritated them. Led by Pang Xun, some soldiers mutinied and marched back north. They have unimpeded access to the area by the winter of 868. The local civil governor refused Pang's demand to have the hatred officers removed, and a military confrontation ensued. Thousands of local peasants joined the rebels. They took the prefectural city of Xuzhou, captured the civil governor, and killed those officers. Pang acquired a considerable following. Still, the rebellion was suppressed a year later eventually. Wuning was renamed