Third-generation head of the Hōjō clan

Hōjō Ujiyasu

北条氏康

birth year unknown – 1571

Third-generation head of the Hōjō clan. Succeeding to leadership in 1541, he defeated the combined forces of the Yamanouchi and Ogigayatsu Uesugi clans and the Koga kubō at the Battle of Kawagoe in 1546. The Ogigayatsu Uesugi fell from this defeat, and the Hōjō achieved major superiority in Musashi. Ujiyasu's significance lay not in a single victory but in establishing, through tax reforms in 1550 and the 1559 Odawara Shozai Shoryōchō, the structure for imposing military and construction obligations, and in placing his sons in territorial branch castles to manage the domain as regional units. From the Kai-Sagami-Suruga Tripartite Alliance of 1554 through the peace accord between Echigo and Sagami, he restructured diplomatic relations, and after transferring leadership to Ujimasa at the end of 1559, he served as 'Gohonjōsama' (the true lord), acting as regent until his death in 1571.

Sources　小田原市「氏康の領国経営」／おだわらデジタルミュージアム「北条氏康」／小田原市「北条五代にまつわる歴史」／川越市「河越夜戦跡」／鉢形城歴史館「後北条の戦略」／静岡市歴史博物館「今川義元」／北条氏康書状（永禄12年3月13日）