Early history Kazusa was originally part of a larger territory known as , which was divided into "upper" and “lower” portions (i.e. Kazusa and Shimōsa) during the reign of
Emperor Kōtoku (645–654). It was well known to the Imperial Court in
Nara -period Japan for its fertile lands, and is mentioned in Nara period records as having supplied
hemp to the Court. Kazusa was divided into 15 counties, of which the four counties comprising the district of Awa were separated in 718 into a separate province. The exact location of the capital of Kazusa is not precisely known, but is believed to have been somewhere within the borders of the modern city of
Ichihara, Chiba. The ruins of the
kokubun-ji, or
provincial temple, of Kazusa has been located in the Sōza district of Ichihara. The
kokubun-ji was first excavated in 1949, and is on a plateau above the
Yōrō River in close proximity to
Tokyo Bay. The site is protected as a
Designated Historic Site of Japan. However, the
Ichinomiya of Kazusa Province is the
Tamasaki Shrine in what is now the town of
Ichinomiya, Chiba, on the opposite coast of the province. During the
Heian period, the province was divided into numerous
shōen controlled by local
samurai clans, primarily the
Chiba clan, which sided with
Minamoto no Yoritomo in the
Genpei War. During the
Kamakura period, much of the province was under the control of the
Ashikaga clan. By the early
Muromachi period, the area was a highly contested region highly fragmented by various samurai clans. However, by the
Sengoku period, the
Satomi clan had gained control over much of Awa, Kazusa and Shimōsa provinces. The Satomi provided only lukewarm support to
Toyotomi Hideyoshi during the
Battle of Odawara against the
Later Hōjō clan and were subsequently deprived of their holdings in Kazusa and Shimōsa. After the installation of
Tokugawa Ieyasu in
Edo, Kazusa became part of the
Tokugawa clan holdings, and Tokugawa hereditary retainer
Honda Tadakatsu was promoted to
daimyō of
Ōtaki Domain (50,000
koku).
Edo period During the
Edo period, several small
domains were created within the borders of Kazusa, most of which continued to be retained as
tenryō territory owned directly by the
shōgun and administered by various
hatamoto. The entire province had an assessed revenue of 425,080
koku.
Edo period Domains in Kazusa Province }
Abolishment Following the
Boshin War,
Jōzai Domain was abolished for its opposition to the
Meiji Restoration, and six minor domains were created for daimyō dispossessed with the creation of
Sunpu Domain for the ex-
shōgun Tokugawa Yoshinobu. These various domains and
tenryō territories were transformed into short-lived prefectures in July 1871 by the
abolition of the han system, and the entire territory of Kazusa Province became part of the new Chiba Prefecture on June 15, 1873. ==Historical districts==