It could be interpreted easily by observing the period between FUJIWARA no Mototsune, who was said to have built the foundation of the regent family, to the golden age of FUJIWARA no Michinaga as an example.
例えば摂関家の礎を築いたといわれる藤原基経から、最盛期の藤原道長までの間を見るとそのことが良く解る。