Born in 1543 at Okazaki Castle in Mikawa Province as the eldest son of Matsudaira Hirotada, his childhood name was Takechiyo. At age 6 he was sent to Sunpu as a hostage of the Imagawa clan, then passed through hostage situations under the Imagawa and Oda — circumstances that forged his patience, keen observation, and political thinking. After the Battle of Okehazama in 1560 he broke free from the Imagawa, formed an alliance with Oda Nobunaga, and steadily absorbed Mikawa, Totomi, Suruga, Kai, and Shinano. After Nobunaga's death he maneuvered carefully under Hideyoshi while growing into a great daimyo controlling 2.5 million koku in the Kanto. After Hideyoshi's death he crushed the western forces of Ishida Mitsunari at Sekigahara in 1600, seizing de facto power over Japan. Appointed Seii Taishogun in 1603, he established the Edo Shogunate and just two years later transferred the title to his heir Hidetada, demonstrating the hereditary Tokugawa succession to the world. The Sieges of Osaka in 1614–1615 destroyed the Toyotomi clan and cemented Tokugawa supremacy. He continued to wield real power from retirement at Sunpu Castle and died in 1616 at age 73. After death he was deified as Tosho Daigongen and enshrined at Nikko Toshogu.