Born around 1432, now identified by recent research as a member of the Kyoto Ise clan serving the Muromachi Shogunate—the old image of a wandering ronin has been discredited. After his brother-in-law Imagawa Yoshitada's death in 1476, he intervened in the Imagawa succession dispute and gained a foothold in Suruga. In 1493, exploiting the Meio Coup (a factional conflict within the shogunate), he attacked the Horigoe Kubo and seized Izu Province—a brazen act of gekokujo that later earned him the epithet "the man who opened the Sengoku era." Around 1495 he captured Odawara Castle and advanced into Sagami, then continued expanding across the southern Kanto region. He won over local warrior families with moderate tax demands and the principled governance laid out in his "Twenty-One Articles," a manual of frugality and civil-military balance. He granted his son Ujitsuna the surname "Hojo," founding the Later Hojo dynasty that would dominate Kanto for five generations. He lived to 87 or 88, dying in 1519—a lifespan that bridged the late Muromachi order and the Sengoku era he had helped to create.