the area around present-day yokosuka city has been inhabited for thousands of years. archaeologists have found stone tools and shell middens from the japanese paleolithic period and ceramic shards from the jōmon and kofun periods at numerous locations in the area. during the heian period, local warlord muraoka tamemichi established kinugasa castle in 1063. he became the ancestor of the miura clan, which subsequently dominated eastern sagami province for the next several hundred years. 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 1518 attack by hōjō sōun. following the defeat of the later hōjō clan at the battle of odawara, toyotomi hideyoshi transferred tokugawa ieyasu to take control over the kantō region, including yokosuka in 1590.