Fanzhen

'region town'), was a system of decentralized governance in Medieval China that involved strategic military districts and commanderies along the empire's borderland areas administered through highly autonomous regional governors known as jiedushi during the Tang dynasty (618–907 CE).

Primarily designed to be buffer regions shielding the politically and economically vital heartlands, these districts came under the control of increasingly influential provincial military commissioners, who became ambitious warlords, rebels and even usurpers during the late Tang period.

Precursors of fanzhen started at least as early as the Western Han dynasty, during which trusted members of the Liu royal family were given fiefs around the Guanzhong region, known as fanguo (Chinese: 藩国; lit.

However, due to the Rebellion of the Seven States, since the reign of Emperor Wu the Han court started to replace the royal feudal lords with centrally sanctioned officials (who were selected via recommendations from local administrators) as regional governors.

During the late reign of Emperor Xuanzong of Tang, control of the fanzhen devolved from central authority into the hands of long-term local officials and military leaders, who often passed down their position to kins and at times became clans powerful enough to overshadow the imperial court.