Tokugawa Ieyasu was the founder and first shōgun of the Tokugawa shogunate of Japan, which ruled from 1603 until the Meiji Restoration in 1868. He was one of the three "Great Unifiers" of Japan, along with his former lord Oda Nobunaga and fellow Oda subordinate Toyotomi Hideyoshi. The son of a minor daimyo, Ieyasu once lived as a hostage under daimyo Imagawa Yoshimoto on behalf of his father. He later succeeded as daimyo after his father's death, serving as ally, vassal and general of the Oda clan, and building up his strength under Oda Nobunaga.

Shogun, officially sei-i taishōgun , was the title of the military rulers of Japan during most of the period spanning from 1185 to 1868. Nominally appointed by the Emperor, shoguns were usually the de facto rulers of the country. Although during part of the Kamakura period and Sengoku period, shoguns were figureheads themselves, with real power in the hands of the shikken (執権) of the Hōjō clan and kanrei (管領) of the Hosokawa clan. In addition, Taira no Kiyomori and Toyotomi Hideyoshi were leaders of the warrior class who did not hold the position of shogun, the highest office of the warrior class, yet gained the positions of daijō-daijin and kampaku , the highest offices of the aristocratic class. As such, they ran their governments as its de facto rulers.