Mikawa is mentioned in records of the
Taika Reform dated 645, as well as various
Nara period chronicles, including the
Kujiki, although the area has been settled since at least the
Japanese Paleolithic period, as evidenced by numerous remains found by archaeologists. Early records mention a "Nishi-Mikawa no kuni" and a "Higashi-Mikawa no kuni", also known as . Although considered one administrative unit under the
Engishiki classification system, this division (roughly based at the Yasaku River) persisted informally into the
Edo period. The exact location of the provincial capital is not known. Traditionally considered to have been located in the area of the modern city of
Toyokawa because of the place name, archaeological investigations at the Hakuho-machi area of
Toyota from 1991 to 1997 have revealed extensive ruins and ceramic shards indicating the possibility that the provincial capital was located there. Furthermore, the ruins of the
Kokubun-ji of Mikawa Province was located in 1999 a short distance away from the Toyota site. On the other hand, the
Ichinomiya of the province,
Toga jinja is located in what is now part of Toyokawa, as well as a temple which claims to be a successor to the original provincial temple. During the
Heian period, the province was divided into numerous
shōen controlled by local
samurai clans. During the
Kamakura period but it came under the control of
Adachi Morinaga, followed by the
Ashikaga clan. For much of the
Muromachi period it was controlled by the
Isshiki clan. However, by the
Sengoku period, the province had fragmented into many small territories largely dominated by the
Matsudaira clan, and contested by the
Imagawa clan to the east and the
Oda clan to the west. It was united under
Tokugawa Ieyasu after the power of the Imagawa had been destroyed at the
Battle of Okehazama. After the creation of the
Tokugawa shogunate, parts of the province were assigned as
feudal domains to trusted hereditary retainers as
fudai daimyōs, with large portions retained as
shihaisho territory administered by various
hatamoto directly under the shogunate. During the Edo period, Mikawa was the only area permitted by the shogunate to produce
gunpowder, which led to its modern fireworks industry. The various domains and
tenryō territories were transformed into short-lived prefectures in July 1871 by the
abolition of the han system, and was organized into ten districts by the early
Meiji period cadastral reform of 1869. The entire territory of former Mikawa Province became part of the new Aichi Prefecture in January 1872. After World War II, the territory of former Mikawa Province prospers as the capital of the Japanese automobile industry. ==Historical districts==