Koga Domain

When Toyotomi Hideyoshi defeated the Hōjō at the Siege of Odawara, the area fell into his hands, and was subsequently assigned (along with the rest of the Kantō region) to Tokugawa Ieyasu.

Afterwards, the domain was reassigned every couple of generations to a large number of fudai daimyō clans, spending the longest time under the control of the Doi clan (1633–1681, 1762–1871).

During the Boshin War, the Tokugawa shogunate ordered the domain to provide guards on the foreign settlement at Yokohama.

The final daimyō of Koga, Doi Toshitomo, served as domain governor until 1871, and was awarded the title of shishaku (marquis) under the kazoku peerage system.

As with most domains in the han system, Koga Domain consisted of several discontinuous territories calculated to provide the assigned kokudaka, based on periodic cadastral surveys and projected agricultural yields.