Aiko District, Kanagawa

Aikō District (愛甲郡, Aikō-gun^?) is a district located in central Kanagawa Prefecture, Japan. It currently consists of only one town, Aikawa, and one village, Kiyokawa. The city of Atsugi was formerly part of Aikō District.

Aikō District was one of the ancient subdivisions of Sagami Province, extending from central Sagami north to the border of Musashi Province between the Sagami River and the Tanzawa Mountains. The district offices were located in what is now part of Atsugi. The area was part of a vast shōen controlled by the Oe clan, and their descendents, the Mōri clan of Chōshū from the Heian period through the Sengoku period. It later became a contested area between the late Hōjō clan of Odawara and the Takeda clan of Kai. In the Edo period, it was nominally part of Odawara Domain, although large portions were tenryō territory controlled by the Shogun in Edo through various hatamoto. From 1706, a branch of the Ōkubo clan in Odawara was permitted to establish the Ogino-Yamanaka Domain on a portion of the district. Other portions of the district came under control of Karasuyama Domain of Shimosa Province.