The Fujiwara rose to power by having their sisters and daughters marrying the imperial family.
The Fujiwara family power was not only based on militarism but mainly on family's relationship to the imperial family. This relationship was mantained by the marriage of Fujiwara daughters to emperors. It meant that the Fujiwara daughters were empresses, that their grandsons and nephews were emperors, and that members of their family, including its lesser branches, received all the patronage.