- Born: 1574
- Died: 1607
- Title: Mikawa no Kami
- Other Names: Tokugawa Hideyasu, Matsudaira Hideyasu, Hashiba Hideyasu
Hideyasu was the second son of Ieyasu. He was brought up under the supervision of Toyotomi Hideyoshi and accompanied him on the Kyushu Campaign. Hideyasu was adopted by Yûki Harutomo in 1590, and inherited a 100,000 koku fief in Shimosa from his adoptive father Harumoto. During the Sekigahara Campaign (1600), Hideyasu provided valuable assistance in the containment of Uesugi Kagekatsu and was afterwards transferred to a 67,000 koku fief in Echizen (Kita-no-shô). He was also acting as the keeper of Fushimi castle when he died in 1607, and some have suggested his affinity for the Toyotomi house in which he had been raised contributed to his untimely death. He was succeeded in Echizen by his son Tadanao (1595-1650). A younger son, Tadamasa, is reputed to have taken no fewer then 57 heads at Osaka castle (1614-15).
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005
- Arai Hakuseki, Joyce Ackroyd (trans.), Told Round a Brushwood Fire, University of Tokyo Press (1979), 315n93.
- Ishin Shiryô Kôyô 維新史料綱要, vol 2 (1937), 186.