Ichinomiya Castle was a mountain-top fortification built by the Satomi clan, rulers of most of the Bōsō Peninsula during the Sengoku period as protection for their northern holdings in eastern Kazusa Province.
Following the Battle of Odawara in 1590, the Kantō region was assigned to Tokugawa Ieyasu by the warlord Toyotomi Hideyoshi, who also restricted the Satomi to Awa Province for their lukewarm support of his campaigns against the Later Hōjō clan.
Tokugawa Ieyasu appointed Honda Tadakatsu, one of his hereditary retainers, to be daimyō of the new 100,000 koku Ōtaki Domain, and the old fortifications at Ichinomiya were abandoned.
The final daimyō of Ichinomiya Domain, Kanō Hisayoshi, was a strong supporter of rangaku, and imported western weapons to modernize his forces.
Under the new Meiji government he was appointed domain governor, until the abolition of the han system in July 1871 and subsequently became a viscount under the kazoku peerage.