During the heian period, what was the role of nobility in the development of japanese society?

In the Heian period, the Fujiwara nobility played a dominant part to protect their lands. At some time they became regents in court that made them powerful. In history, they had climbed up the political ladder through coup de tat. Fujiwara family had scattered in time at Kyoto. In its time of ruling at had influenced Japan in its culture; through religion such as Buddhism and Shintoism, a writing system and literature.