A later Roman division of the empire. The four prefectures were governed by two emperors and their two deputies (caesars). This sytem was disolved under emperor Constantine I in the early 4th century AD.
The administrative area below the level of a province or region and above the level of a county. The “TAR” is divided into six prefectures. A “Tibetan Autonomous Prefecture” (Chinese: Zang zu Zizhizhou) is a prefecture outside the “Tibetan Autonomous Region” but still considered to include a predominantly Tibetan population.
The term prefecture (from the Latin Praefectura) indicates the office, seat, territorial circonscription of a Prefect. In English the term prefecture is also used to refer to offices deemed equivalent in other languages' cultural traditions.