Nobutsuna was born in 1596, the son of
Ōkōchi Hisatsuna, a senior retainer of
Tokugawa Ieyasu. He was adopted as the heir of his uncle,
Matsudaira Masatsuna, in 1601. After being introduced to
Hidetada and Ieyasu, he was appointed as page to Ieyasu's grandson
Iemitsu. He was greatly admired by Iemitsu, and renowned within the Tokugawa administration for his sagacity. In the early years of his service, he was a
hatamoto; he later became a daimyo. In 1623, he received the court title of
Izu no Kami. He became daimyo in 1633, receiving the
Oshi Domain as his fief. After the failure of
Itakura Shigemasa to subdue the rebellion at
Shimabara in 1637–38, Nobutsuna took command of the allied armies laying siege to
Hara Castle, bringing the campaign to a successful conclusion. In his later years, he joined senior Tokugawa officials such as
Hoshina Masayuki in supporting the underaged 4th shōgun,
Ietsuna. In 1653-54, Nobutsuna, in his role as councillor, oversaw the construction of the
Tamagawa Aqueduct, which relieved water supply issues in
Edo when the
sankin-kōtai policy requiring lords to set up residences in the capital made the existing water supply system inadequate. ==In popular culture==