Chāng Prefecture

Changzhou or Chang Prefecture was a zhou (prefecture) in imperial China, centering on modern western Chongqing, China. It existed (intermittently) from 785 until 1290.

Geography
The administrative region of Chang Prefecture in the Tang dynasty was in modern western Chongqing (which borders Sichuan). It probably includes parts of modern:
 * Dazu District
 * Rongchang District
 * Yongchuan District