The regency is a form of government during the Heian period where actual power was long monopolized by a deputy or adviser to the emperor from Yoshifusa's line in the Fujiwara family (the Northern House of the Fujiwara clan), who was installed as a regent, a chancellor or a nairan (private inspection) from generation to generation.
摂関政治（せっかんせいじ）とは、平安時代に藤原氏（藤原北家）の良房流一族が、代々摂政や関白あるいは内覧となって、天皇の代理者、又は天皇の補佐者として政治の実権を独占し続けた政治形態である。