The area of modern Sagamihara has been settled since ancient times, and has a number of remains from the
Japanese Paleolithic period and
Kofun period have been found. It was home to the Yokoyama clan, one of the seven warrior clans of the
Musashi region during the early
Kamakura period. During the
Edo period, the lands around Sagamihara were
tenryō territory theoretically administered directly by the
Tokugawa Shogunate in
Edo; however, in reality, the area was a patchwork of small fiefs held by various
hatamoto, as well as exclaves under the control of the Ogino-Yamanaka Domain and Karasuyama Domain. After the
Meiji Restoration, the eastern portion was part of
Kōza District, and the western portion was part of
Tsukui District. The Kōza District portion was administratively divided into six villages on April 1, 1889 with the creation of the modern municipalities system. The area was the location of extensive training facilities and arsenals of the
Imperial Japanese Army during the 1930s. These villages were merged on April 29, 1941, together with neighboring
Zama Town to create Sagamihara Town. At the time of its formation, it was the largest town in Japan in terms of area. On September 1, 1948, Zama was administratively separated into Zama Town. The remaining portion became Sagamihara City on November 20, 1954. The city population had grown steadily, partly due to local industrial development, and partly due to the city's excellent transportation infrastructure connecting it to
Yokohama, Tokyo and
Hachiōji. It was designated a
core city with increased autonomy in 2003. On March 20, 2006, Sagamihara absorbed the towns of
Tsukui and
Sagamiko (both from
Tsukui District). The merged city consisted of two geographically separate areas, as two other towns of Tsukui District (
Fujino and
Shiroyama) elected to remain separate. A further merger on March 11, 2007, joined Fujino and Shiroyama with Sagamihara, thus geographically unifying the city, and dissolving former Tsukui District. In 2007, the population of Sagamihara exceeded 700,000. In 2010, Sagamihara was redesignated as a
government ordinance city and split into three wards Midori-ku, Chūō-ku, and Minami-ku. On July 25, 2016, 19 people were killed and 26 injured in
a mass stabbing incident at a disabled care home in the city by Satoshi Uematsu, the perpetrator. ==Government==