Background
Ōkubo was born in Kagoshima, Satsuma Province, (present-day Kagoshima Prefecture) to Ōkubo Juemon a low-ranking retainer of Satsuma daimyō Shimazu Nariakira.
Ōkubo was born in Kagoshima, Satsuma Province, (present-day Kagoshima Prefecture) to Ōkubo Juemon a low-ranking retainer of Satsuma daimyō Shimazu Nariakira.
The eldest of five children, he studied at the same local school with Saigō Takamori, who was three years older.
Shimazu Nariakira recognized Ōkubo's talents and appointed him to the position of tax administrator in 1858. When Nariakira died, Ōkubo joined the plot to overthrow the Tokugawa shogunate.
He became one of the mikado's principal ministers, and in the Satsuma troubles which followed he was the chief opponent of Saigo Takamori. In 1866, he met with Saigō Takamori and Chōshū Domain's Kido Takayoshi to form the secret Satchō Alliance to overthrow the Tokugawa.
But the suppression of the Satsuma rebellion brought upon him the personal revenge of Saigo's sympathizers, and in the spring of 1878 he was assassinated by six clansmen. Okubo was one of the leading men of his day, and in 1872 was one of the Japanese mission which was sent round the world to get ideas for organizing the new regime.
Ōkubo was one of the most influential leaders of the Meiji Restoration and the establishment of modern governmental structures. Briefly, for a time he was the most powerful man in Japan. He was one of the five great nobles who led the revolution in 1868 against the shogunate. He is regarded as one of the main founders of modern Japan.
He married Yoneda Yaeko and had two children, Yasushi (b. 1934) and Shigeko (b. 1936). Yasushi married Matsudaira Naoko (b. 1940) and had a daughter, Akiko (b. 1965). Okubo also had four illegitimate children by a mistress.