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.
These regions were primarily created to act as defensive buffers around the vital heartlands, which later came under the influence of increasingly dominant provincial military leaders who transformed into powerful warlords, rebels, and even power-seekers during the late Tang era.