Aikō District, Kanagawa

The area was part of a vast shōen controlled by the Ōe clan, and their descendants, the Mōri clan of Chōshū from the Heian period through the Sengoku period.

In the Edo period, it was nominally part of Odawara Domain, although large portions were tenryō territory controlled by the shōgun 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 Shimōsa Province.

With the abolition of the han system in 1871, former Ogino-Yamanaka Domain became Ogino-Yamanaka Prefecture, and subsequently part of the short-lived Ashigaru Prefecture.