Then, the Fujiwara clan and the Minamoto clan, the relatives of the Emperor, almost created a monopoly of the Giseikan (a legislative organ), and it is worthy to note that the direct descent of the Northern House of the Fujiwara clan achieved the position of Sessho Kanpaku (regent and chief adviser to the Emperor) in the late ninth century, which made them receive and deal with the political discretion of the Emperor; and they were also successful in making the position hereditary.
そのうち、天皇のミウチである藤原氏と源氏が議政官（公卿）をほぼ独占し始め、特に藤原北家嫡流は9世紀後半に天皇の政治決定権を受任・代行しうる摂政・関白の地位を獲得し、その地位を世襲することに成功した。