The Nitta clan was one of several major families descended from the Seiwa Genji, and numbered among the chief enemies of the Hōjō clan regents, and later the Ashikaga shogunate. The common ancestor of the Nitta, Minamoto no Yoshishige (1135–1202), was the elder brother of Minamoto no Yoshiyasu, the common ancestor of the Ashikaga clan. Yoshishige was a landowner in the Nitta District of Kōzuke Province in present-day Gunma Prefecture. Yoshishige supported Minamoto no Yoritomo (1147–1199) in the Battle of Ishibashiyama of 1180 against the Taira clan.