He was born the second son of FUJIWARA no Kanehira, but he later became an adopted child of FUJIWARA no Sanesuke, who was Kanehira's little brother and was adopted by his grandfather FUJIWARA no Saneyori.
藤原懐平の二男として生まれるが、時期は不明ながら、懐平の弟でその祖父藤原実頼の養子となっていた、実資の養子となる。