Three Fanzhen of Hebei
The Three Fanzhen of Hebei (Chinese: 河朔三镇; pinyin: Hé shuò sān zhèn) were three regions of what is now Hebei, China governed by powerful jiedushi during the Tang dynasty (618–907). After the devastating An Lushan Rebellion, this area became virtually independent of the central government, as these regions were controlled by ex-rebel generals who had substantial territory and forces. The independence of these fanzhen threatened the central government of the Tang dynasty.
During and after the An Lushan Rebellion, the Tang court lost control of vast swathes of territory and a number of defense commands evolved into autonomous kingdoms, their military commissioners became warlords, only nominally subservient to the Tang court. Particularly recalcitrant were Chéngdé (成德), Lúlóng (盧龍) and Wèibó (魏博) in the Hebei area. The central court was all but helpless in the northeast. In the south, however, it took a much more aggressive stand against such defense commands as Zīqīng (淄青) (mainly in Shandong), Biànsòng (汴宋) (in east Henan), and Huáixī (淮西) (in south Henan), which posed a more immediate and palpable threat to the transportation of strategic grains through the Grand Canal, on which the court depended.
During Emperor Xianzong's reign this region was briefly subdued by the central government, but after his death it became independent again. By the reign of Emperor Wenzong, the central government had lost all control over this region. The situation was summed up thus by Tang dynasty's chancellor Niu Sengru:
"Ever since the Anshi Rebellion, the three Fanzhen have not been part of the country. Although Liu Chong briefly gave the area to the central government, in the end it became independent and 80 million strings of cash were wasted. These regions are fought over frequently; one day Zhicheng has it, the next day Daiyi. As long as the jiedushi can fend off the northern barbarians, we will not care about its allegiance."