He was born in Totomi, the second son of Tokugawa Ieyasu. His mother is said to have been Lady Oman. His childhood name was Ogii. A tale says Ieyasu did not acknowledge him at first and met him only through his elder brother Nobuyasu's mediation, but this is not certain.
His elder brother Nobuyasu, suspected by Oda Nobunaga, was driven to take his own life. At 5, Hideyasu was now in line to be Ieyasu's heir. But the succession later went to his younger brother Hidetada, and Hideyasu took another path.
After the Komaki-Nagakute campaign, as a token of peace between Ieyasu and Hashiba Hideyoshi, he was sent to Hideyoshi as an adopted son, in effect a hostage. Taking one character each from Hideyoshi's and Ieyasu's names, he became Hashiba Hideyasu and grew up in Osaka.
He joined Hideyoshi's Kyushu campaign and is said to have distinguished himself in attacks such as on Ganjaku Castle in Buzen. It was his first battle, at 13. He became a youth of noted valor, respected even within the Toyotomi house.
Partly because Hideyoshi now had a son of his own, Tsurumatsu, he was adopted by Yuki Harutomo of an old Shimousa house and succeeded to the Yuki. Taking the name Yuki Hideyasu, he became a daimyo of over 100,000 koku and gained a new standing as heir of a northern Kanto house.
For Hideyoshi's invasion of Korea he led troops to Nagoya Castle in Hizen. He did not cross the sea, but among daimyo gathered from across Japan he stood out as a young lord tied to both the Tokugawa and the Toyotomi.
At Sekigahara, while Ieyasu marched west, Hideyasu stayed at Utsunomiya in Shimotsuke to block Uesugi Kagekatsu of Aizu from advancing south. He did not fight at the front, but securing the east helped the Tokugawa victory.
For his service at Sekigahara he received about 670,000 koku centered on Echizen. Based at Kitanosho, later Fukui, he developed its castle and town. As Ieyasu's son he was entrusted with the great task of guarding Kyoto from the Hokuriku.
Around this time he is said to have taken the Matsudaira surname, and his house came to be called the Echizen Matsudaira. While his younger brother Hidetada became 2nd shogun, Hideyasu, as elder brother, was a pillar of the family, entrusted with posts such as keeping Fushimi Castle.
He died of illness in Echizen at the young age of 33. Many are said to have mourned the loss of his valor and ability. The Echizen Matsudaira continued, and at the end of the Edo period his descendant Matsudaira Shungaku (Yoshinaga), lord of Fukui, played a great role in national politics.
Oda NobunagaTokugawa IeyasuUesugi KagekatsuMatsudaira Shungaku (Yoshinaga)
Tachibana MuneshigeKuroda NagamasaYodo-donoItō MancioHasekura TsunenagaUkita HideieKobayakawa HideakiToyotomi Hideyori
People of the Sengoku/Azuchi-Momoyama period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.