The term prefecture has been used to denote a self-governing body or area since the time of Constantine I, who divided the Roman Empire into 4 districts (each divided into dioceses). Much like a state or city, these were largely self-governed; however each owed allegiance to Rome. A prefect was the head of a prefecture.
In the Japanese system, the word prefecture is used for translating references to an administrative district, ken (県), which is about the size of a county.
The local self-governing system of Japan consists of 2 classes: prefectures as the large area local governing units and municipalities the basic local governing units. In the Eastern sense, the administrative segregation of a unified nation is usually trifold: the nation, large area local governing units, and basic local governing units. Japan fits this pattern.
Japan is divided into 47 prefectures and each prefecture is further divided into municipalities. These prefectures and municipalities have no overlapping districts or uncovered areas. In short, all the residents in Japan are sure to belong to one prefecture and one municipality.
These prefectures and municipalities are not merely set up as the nation's administrative section, but also as corporate bodies independent from the country that possesses their own basic governing areas and local residents as their constituents. They hold administrative power within the districts in question. In Okinawa, Nagasaki and Hokkaido, subprefectures are used as special administrative units because such regions are too large or remote for a single prefectural government to govern.
The current prefecture system in Japan was settled in Meiji era after the new government abolished feudal clans or Han. That is called "Abolition of the Han system". See Meiji era in History of Japan for historical background of this event.
When used in the context of Chinese history, especially China before the Tang Dynasty, the word "prefecture" is used to translate xian (县/縣). This unit of administration is translated as "county" when used in a contemporary context.
See County of China for more information on the xian of China.
In the context of Chinese history during or after the Tang Dynasty, the word "prefecture" is used to translate zhou (州), another ancient unit of administration in China.
See Zhou (political division) for more information on the zhou of China.
In modern-day People's Republic of China, the prefecture (地区; pinyin: dìqū) is an administrative division found in the second level of the administrative hierarchy. In addition to prefectures, this level also includes autonomous prefectures, leagues, and prefecture-level cities. The prefecture level comes under the province level, and in turn oversees the county level.
See Prefecture of China for more information on modern prefectures in China.
In France, a préfecture is the capital city of a département. By extension, it is also the name of one of the governing bodies of the département. The civil servant in charge is the préfet. The préfecture is an administration that belongs to the Interior ministry, and is therefore in charge of the delivery of the identity card, driving licenses, passports, residence and work permits for foreigners, car registration, registration of the associations (creation, status modification, dissolution), and of the management of the police and of the firefighters. The préfet can make arrêtés, which are legal texts written for the application of the law, e.g. to close a building that does not conform to the safety rules, or to modify vehicular traffic regulations (speed limit, authorisation for construction). The other governing body is the Conseil Général, which is in charge of the building and maintenance of schools and roads, the financial assistance to dependent people (disabled and elderly), promotion of the economical local development... Préfecture It is also the name of the building where the préfet is based.
There are 100 préfectures in France.
There is an exception with Paris (which is itself a département) and the three surrounding départements (called the petite couronne, small crown): those four départements are governed by a single préfecture for law enforcement and security purposes, which is the préfecture de police (PP). The préfet de police has the power of law enforcement for Paris, which is a power of the mayor for the other french cities and towns. Until 1977, Paris had indeed no mayor and was mostly ruled by the préfet de police (a situation inherited from the Paris Commune, 1871).
The départements are divided into arrondissements, themselves divided into cantons. The capital city of an arrondissement is the sous-préfecture. The civil servant in charge is the sous-préfet. The capital city of a canton is a chef-lieu de canton. The cantons have little role except as electoral subdivision.
Modern Greece, under its 1975 Constitution, is divided into 51 nomoi (Greek: νομοι). These are most commonly translated into English as prefectures. Each nomos is headed by a prefect (nomarch), who is elected by direct popular vote.