His birth year was uncertain but is estimated that he was born in 968 or 969 by comparing the age of his siblings and the incident with FUJIWARA no Tadanobu.
生年は不詳であるが、兄弟の年齢や後述の藤原斉信のエピソードから安和元年（968年）もしくは同2年（969年）と推定される。