Sadamasa was the son of Okudaira Sadayoshi. He served under Ieyasu in a number of battles and took two heads at the Battle of Anegawa. He was briefly forced to join Takeda Shingen around 1572 but following Shingen's death the following year returned to the Tokugawa, abandoning Tsukude castle. As a result of his turn-coating, Takeda Katsuyori ordered Sadamasa's family seized and crucified. He held Nagashino castle for the Tokugawa in 1575 and resisted the Takeda attempts to bring it down in June of that year, a campaign that culminated in the Battle of Nagashino. Sadamasa later married Tokugawa Ieyasu's daughter and in 1590 was given a 30,000-koku fief at Miyazaki in Kôzuke Province. His daughter married Okubo Tadatsune.
- Initial text from Samurai-Archives.com FWSeal & CEWest, 2005