Minamoto no Yoritomo, legendary warrior and founder of the Kamakura shogunate, was whom Ieyasu claimed to be a descendant of. 
With him are two other worthy Toyotomi Hideyoshi, Ieyasu's mentor, and the great 12th-century warrior Minamoto no Yoritomo, who founded the Kamakura shogunate and whom Ieyasu claimed as an ancestor.