Yes, that's correct! The Fujiwara clan was a powerful and influential family in Japan during the Heian period (794-1185). They adeptly used marriage as a political tool to secure their dominance over the imperial court. By marrying their daughters to emperors and other high-ranking officials, they established close links to the imperial lineage, allowing them to exert significant influence over the government.
The positions of regent (Sesshō) and chancellor (Kampaku) were particularly important for the Fujiwara, as they allowed family members to effectively govern on behalf of the emperor, especially when the emperor was too young or otherwise unable to rule. This strategy of marrying into the imperial family and holding these key positions enabled the Fujiwara to maintain a remarkable degree of control over the political landscape of Japan for several generations. Their influence helped shape various aspects of court culture, politics, and even religion during the Heian period. However, their power eventually declined as new warrior classes emerged and the political landscape evolved, leading to the rise of the samurai class and the establishment of the shogunate system.