the miura clan supported minamoto no yoritomo in the foundation of the kamakura shogunate, but were later annihilated by hōjō tokiyori in 1247. however, the family name was reassigned to a supporter of the hōjō clan, and the miura continued to rule miura peninsula through the muromachi period until their defeat at arai castle in a 1516 attack by hōjō sōun.