He was the son of Mototoki HOJO, the 13th Regent to the Shogun, and a member of the Hojo clan (Fuonji branch) which had split from the Gokurakuji branch of the Hojo clan.
北条氏(極楽寺流)の分かれ北条氏(普恩寺流)で、第13代執権の北条基時の子。