The commandery (郡 jùn) was the main administrative unit below the province. It was headed by a Grand Administrator and contained several counties, and it was the level at which much day-to-day governance, recruitment, and military organisation took place.
Role in administration
Provinces (州) were the highest regional tier; within each province, commanderies formed the next level. Figures in the Records of the Three Kingdoms are often identified by their native commandery (e.g. from Pei Commandery, Runan Commandery) or by commanderies they governed or campaigned in. Control of key commanderies was essential to controlling a region.
In the Three Kingdoms
Wei, Shu, and Wu all retained the commandery as an administrative unit. Names such as Hanzhong Commandery, Jingzhao Commandery, or Wu Commandery appear in accounts of battles, appointments, and territorial changes throughout the period.