Tanaka Domain
Honda Masamori was born as the 7th son of the 5th "daimyō" of Tanaka Domain (Honda Masaoki). In 1856, he was adopted by his elder brother Honda Masahiro as heir, and was received in formal audience by Shogun Tokugawa Iesada in 1857, who awarded him the courtesy title of "Kii-no-kami" and court rank of Junior 5th Rank, Lower Grade. On the death of his brother in 1860, he became "daimyō" of Tanaka Domain. In 1862, he was appointed to the newly-created post of "Gakumonjo-bugyō". In 1863, he built a "jin'ya" at the domain's exclave in Shimōsa Province, and many of his retainers from the domain's "shimo-yashiki" in Fukagawa, Edo relocated to the new location. In 1864, he was appointed "Sunpu jōdai", a post which he held into the Boshin War. Through mediation of Owari Domain, he agreed to surrender Sunpu Castle to the new Meiji government in June 1868.