* Image is for illustrative purposes only.Okudaira Nobumasa
奥平信昌
Daimyo
Description
The Okudaira, Warrior House of Mikawa
Okudaira Nobumasa was born in 1555 (Kōji 1) as the son of Okudaira Sadayoshi. The Okudaira were a local warrior house based at Tsukude in Mikawa Province, caught between two great powers — the Takeda to the east and the Tokugawa to the west — and repeatedly forced to shift their allegiance. Nobumasa's career is itself the story of how such a borderland house, through a single decision, came to hold a status equivalent to that of the Tokugawa hereditary vassals.
Return to the Tokugawa and the Execution of the Hostages
Around 1573 (Genki 4), acting on Oda Nobunaga's advice, Tokugawa Ieyasu sought to draw the Okudaira to his side by offering Nobumasa betrothal to his eldest daughter Kamehime along with a grant of territory. Nobumasa accepted, divorced his wife Ofū — who had been sent to the Takeda as a hostage — and returned to Tokugawa allegiance. In retaliation for the defection, Takeda Katsuyori executed three hostages, including Nobumasa's former wife and his younger brother. The Okudaira's turn to the Tokugawa was built upon these sacrifices.
The Siege of Nagashino Castle
In the fifth month of 1575 (Tenshō 3), Takeda Katsuyori invested Nagashino Castle with an army of fifteen thousand. Nobumasa, now castellan, held the defenses with a far smaller force and sent his retainer Torii Sune'emon through the encirclement to request relief from Ieyasu and Nobunaga at Okazaki. Sune'emon accomplished the mission at the cost of his life, delivering confirmation that relief was coming and sustaining the garrison's morale. Nobumasa withstood the Takeda assault until the allied Oda–Tokugawa army arrived, and on the twenty-first day of that month the allies won the decisive engagement at Shitaragahara. Without the castle holding out, that decisive battle could not have been fought on those terms.
The Grant of the Daihannya Nagamitsu
For his service at Nagashino, Nobumasa received from Nobunaga the character "Nobu" for his name — becoming Nobumasa — and from Ieyasu the celebrated sword known as the Daihannya Nagamitsu. The tachi is the work of Nagamitsu of the Osafune school in Bizen Province, with a blade length of 73.6 cm and a curvature of 3.0 cm. In the Muromachi period it was appraised at the extraordinary price of six hundred kan, and from this it was named after the Great Prajñāpāramitā Sutra, which comprises six hundred scrolls. Its transmission began with the Ashikaga shogunal house; it was bestowed by Ashikaga Yoshiteru upon Miyoshi Nagayoshi, later passed into the hands of Oda Nobunaga, was presented by Nobunaga to Tokugawa Ieyasu for his service at the Battle of Anegawa, and was then given to Nobumasa for Nagashino. That a sword which had passed among the rulers of the realm should be conferred for one castellan's defense indicates how highly that siege was valued. The blade later descended in the house of Matsudaira Tadaaki — Nobumasa's youngest son, adopted by Ieyasu — at the Oshi Domain. It was designated a National Treasure on 9 June 1951 and is now held by the Tokyo National Museum.
Marriage to Kamehime and Advancement
In the seventh month of 1576 (Tenshō 4), Ieyasu's eldest daughter Kamehime married Nobumasa, and this union with the Tokugawa house greatly raised the standing of the Okudaira. When the Tokugawa were transferred to the Kantō in 1590, he received thirty thousand koku at Miyazaki in Kanra District, Kōzuke Province, and in 1601 he was transferred and raised to one hundred thousand koku at Kanō in Mino Province.
Sekigahara, the Kyoto Shoshidai, and Later Years
Nobumasa took part in the Battle of Sekigahara in 1600, sending a kinsman as an inspecting officer into Kobayakawa Hideaki's camp. After the battle he served as Kyoto Shoshidai and arrested Ankokuji Ekei, the diplomat-monk of the Western Army. In 1602 he retired at Kanō, passing the domain to his third son Tadamasa. He died on the fourteenth day of the third month of 1615 (11 April), at the age of sixty-one. His sons included Iemasa, Matsudaira Ieharu, Tadamasa, and Matsudaira Tadaaki. As the commander who held Nagashino Castle, and as a name inscribed in the transmission of the National Treasure Daihannya Nagamitsu, Nobumasa occupies a secure place in the history of the Japanese sword.