thumb|right|250px|Chōsei District, Chiba as of 2010

is a district located in Chiba Prefecture, Japan. As of September 2010, the district has an estimated population of 63,382 and a density of 279 persons per km<sup>2</sup>. The total area was . The district formerly included all of the city of Mobara and a small portion of the city of Isumi.

Towns and villages

  • Chōnan
  • Ichinomiya
  • Mutsuzawa
  • Nagara
  • Shirako
  • Chōsei

Neighboring municipalities

  • Mobara
  • Ichihara
  • Isumi
  • Ōtaki
  • Ōamishirasato

Geography

Chōsei District occupies an area of central Chiba Prefecture to the east of the Bōsō Peninsula. The west of the district ranges from the Bōsō Hill Range to the Kujūkuri Plain; the east of the district runs along the broad coast of the Kujūkuri Beach on the Pacific Ocean.

History

Early period

During the Edo period, almost all of the area present-day Chōsei District was tenryō territory under direct control of the central government and administered by various hatamoto, with the exception of Ichinomiya, most of which was under the rule of Ichinomiya Domain, a minor feudal domain of the Tokugawa shogunate ruled by the Kano clan.

Modern period

Chōsei District was created on April 1, 1889 out of the merger of the short-lived early Meiji period districts of Nagara (3 towns, 17 villages) and Kamihabu (1 town, five villages). The administrative seat of the district was located in Mobara.