His mother was the daughter of FUJIWARA no Nagatada who was Sangi and her sister married FUJIWARA no Mototaka who was also In no Kinshin of Emperor Toba and she gave birth to FUJIWARA no Tadataka.
母は参議藤原長忠の娘で、その姉妹はやはり鳥羽院近臣の藤原基隆に嫁ぎ、藤原忠隆を生んでいる。