He started to dominate the power as a maternal relative of the emperor for generations from around when FUJIWARA no Moshi, the daughter of FUJIWARA no Kinnari, the third, became an adopted daughter of FUJIWARA no Yoshinobu and married Emperor Gosanjo to have the child, the Emperor Shirakawa.
3代目の藤原公成の娘藤原茂子が藤原能信の養女として後三条天皇に入内し白河天皇を生んだ頃から代々の天皇の外戚として権勢を振るうようになる。