Administrative divisions of the Tang dynasty

The Tang dynasty of China administered territory using a hierarchical system of three descending divisions: circuits (dào 道), prefectures (zhōu 州), and counties (xiàn 縣). Prefectures have been called jùn (郡) as well as zhōu (州) interchangeably throughout history, leading to cases of confusion, but in reality their political status was the same. The prefectures were furthered classified as either Upper Prefectures (shàngzhōu 上州), Middle Prefectures (zhōngzhōu 中州), or Lower Prefectures (xiàzhōu 下州) depending on population. An Upper Prefecture consisted of 40, 000 households and above, a Middle Prefecture 20, 000 households and above, and a Lower Prefecture anything below 20, 000 households. Some prefectures were further categorized as bulwark prefectures, grand prefectures, renowned prefectures, or key prefectures for strategic purposes. A superior prefecture was called a fu (府).

The scope and limits of each circuit's jurisdiction and authority differed greatly in practice, and often individual circuit inspectors' powers and autonomy grew to a point that the administrative system became popularly known as the "Three Divisions of Falsehood" (虛三級). As Tang territories expanded and contracted, edging closer to the period of Five Dynasties and Ten Kingdoms, administrative records of these divisions became poorer in quality, sometimes either missing or altogether nonexistent. Although the Tang administration ended with its fall, the circuit boundaries they set up survived to influence the Song dynasty under a different name: lù (路).