The lord of Okutono in the Mikawa domain (Aichi Prefecture) and the lord of Tanokuuchi in the Shinano domain (Nagano Prefecture). After learning Dutch and French, he became a Rikugun Bugyo (a Magistrate of the Army）, and in 1866 he became the President of the Army. In 1868, he changed his surname to Ogyu after his ancestral estate. He served the Meiji government and contributed to the establishment of the medal system. During the Seinan War in 1877, he founded Hakuaisha with SANO Tsunetami, laying the foundation for the Japanese Red Cross Society. He received the title of Earl.