Kai Province

Kai Province
Kai Province.

Kai Province

Kai Province (甲斐国) was once a Province of Japan, located in what is now Yamanashi Prefecture.12

Established historically during the Taika Reforms,1 it is said this area was also visited previously by Yamato Takeru when he visited from the east.2 Geographically the entire Province is split in two by mountains, with the area being famous for its fabric and black horses.2

By the time of the Heian Period member of the Minamoto Clan settles here, with Minamoto no Yoshimutsu acting as Governor of Kai for a time. The descendants from here of the Minamoto Clan are known as the Kai Genji, with the dominant line of this family being the Takeda Family.1

During the Kamakura Period, the Takeda Family were the leading power in the region acting as shugo1 (Military Governors) until the Azuchi-Momoyama Period under the rulership of Takeda Katsuyori. After several battles againsts other clan leaders by Katsuyori’s father Takeda Shingen, including the Battle of Mitakagahara in 1573 in which the Takeda won against Oda Nobunaga, they were ultimately defeated and destroyed in 1582 following the Battle of Nagashino the year before.2

After the death of Nobunaga control of the region was overseen by Toyotomi Hideyoshi and then Tokugawa Ieyasu.1

By the Edo Period the area was under the control of the Tokugawa Shogunate.12

The Province was name Kōfu Prefecture in 1869 but was renamed again in 1871 to Yamanashi Prefecture.2


1. Kodansha. (1993) ”Japan: An Illustrated Encyclopedia”. Tokyo: Kodansha Ltd.
2. Louis Frederic, translated by Kathe Roth (2002) “Japan Encyclopedia”. London: Harvard University Press.

Former Provinces of Japan
KinaiIzumi * Kawachi * Settsu * Yamashiro * Yamato
TōsandōDewa * Hida * Kōzuke * Mino * Mutsu * Omi * Shimotsuke * Shinano
HokurikudōEchigo * Echizen * Etchū * Kaga * Koshi * Wakasa
San’indōHōki * Inaba * Izumo * Tajima * Tamba * Tango
TōkaidōIse * Kai * Kazusa * Mikawa * Owari * Sagami * Shimōsa * Suruga * Tōtōmi
NankaidōAwa * Iyo * Kii * Sanuki * Tosa
San’yōdōAki * Harima * Mimasaka
SaikaidaōBungo * Chikuzen * Hizen * Hyūga * Iki * Tsushima
Pre-Taihō CodeKibi

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