小田原藩
Ōkubo Tadamasu was a son of Ōkubo Tadatomo, daimyō of Odawara Domain. In 1681, he was appointed a "Sōshaban" (Master of Ceremonies) at Edo Castle, and rose to the position of "Jisha-bugyō" on July 22, 1685. On December 18, 1687, he concurrently received the position of "wakadoshiyori" .