The Ōkubo clan traces its origins to 16th century Mikawa Province.[2] The Ōkubo claimed descent from the Utsunomiya clan, descendants of Fujiwara no Michikane (955–995).[3] Ōkubo Tadatoshi (1499–1581) and his younger brother Ōkubo Tadakazu (1511–1583) were the first to abandon the Utaunomiya name for "Ōkubo". Both brothers were among the seven closest retainers of Matsudaira Hirotada, the father of Tokugawa Ieyasu.
Ōkubo Tadayo (1531–1593), the son of Ōkubo Tadakazu, participated as a general in all the military campaigns of Tokugawa Ieyasu. In 1590, upon the transfer of Ieyasu to the Kantō region, he was rewarded with formal recognition as a daimyō,[2] and the clan was established in the hanofOdawara (45,000 koku) in Sagami Province, where the Ōkubo were made castellans Odawara Castle.[4] The main branch of Ōkubo clan consists of his family and their descendants.[3]
Ōkubo Tadachika (1553–1628) succeeded his father at Odawara, and the revenues of the han had increased to 70,000 koku. In 1614 Tadachika was accused of participation in the plot of Tokugawa Tadateru against his brother, ShōgunTokugawa Hidetada; and the Ōkubo were dispossessed. Tadahicka was confined at HikoneinŌmi Province.[3]
A cadet branch was created in 1601 for Ōkubo Tadasuke (1537–1613), the second son of Ōkubo Tadakazu, who had served as a general in the armies of Tokugawa Ieyasu. Ōkubo Tadasuke was given Numazu Castle and assigned Numazu Domain (20,000 koku) in Suruga Province; however, he died without leaving any heirs, and the domain reverted to the shogunate.[3]
A cadet branch of the Ōkubo was created in 1684. The descendants of Ōkubo Tadatame (1554–1616), the sixth son of Ōkubo Tadakazu, has served as hatamoto to the Tokugawa shogunate. In 1687, Ōkubo Tadataka had amassed a revenue base of 10,000 koku, which qualified him to join the ranks of the daimyō. His son, Ōkubo Tsuneharu (1675–1728) was assigned to Karasuyama Domain (30,000 koku) in Shimotsuke Province in 1725, where his descendants remained until the Meiji restoration. The head of this clan line, Ōkubo Tadayori, was ennobled as a "Viscount" in the Meiji period.[3]
A cadet branch of the Ōkubo was created in 1706. This clan line was instituted for the descendants of Ōkubo Norihiro (1657–1737), who were installed at Ogino-Yamanaka Domain (13,000 koku) in Sagami Province from 1718 through 1868. The head of this clan line was ennobled as a "Viscount" in the Meiji period.[3]
In 1877, a former samurai from Suruga Province, Ōkubo Ichio (1817–1888) was ennobled as a "Viscount" under the kazoku system.[3] Ōkubo Ichio had served as councilor to the last five Tokugawa shōguns, and during the Boshin War, had served as an emissary for Tokugawa Yoshinobu to negotiate the surrender of Edo to imperial forces. Under the Meiji government, he served as appointed governor of Shizuoka (1870) and Kyoto (1875), and as a member of the Genrōin (1877). He was also known as Ōkubo Tadahiro.
Meyer, Eva-Maria. (1999). Japans Kaiserhof in de Edo-Zeit: Unter besonderer Berücksichtigung der Jahre 1846 bis 1867. Münster: Tagenbuch. ISBN3-8258-3939-7
