The Inspector (刺史 cìshǐ) was a regional office in Han and Three Kingdoms administration. Originally an envoy who inspected the commanderies of a province and reported to the court, the role gradually acquired military and fiscal authority and in practice often resembled that of Governor (州牧).
Evolution
Under the Western Han, Inspectors were low-ranking officials who toured a province and reported on the conduct of its administrators. They did not command troops or collect taxes. In the Eastern Han, especially after the Yellow Turban Rebellion, Inspectors were given troops and greater authority. The title Governor (州牧) was sometimes granted to the same man, or the Inspector effectively acted as provincial ruler.
Many figures of the Three Kingdoms period held the post of Inspector: Cao Cao was Inspector of Yan Province at one stage; Sima Lang served as Inspector of Yan Province; Liu Zhang inherited his father’s position in Yi Province, which combined provincial military and civil control.
Relevance to the period
The weakening of the centre and the rise of regional Inspectors and Governors allowed warlords to build power bases in the provinces. Control of a province—often as Inspector or Governor—was a stepping stone to independent rule and to the eventual division of the empire among Wei, Shu, and Wu.