Fujiwara no Michinaga in the context of "Sesshō and Kampaku"

In Japan, the Sesshō (摂政) was a regent who was named to act on behalf of either a child emperor before his coming of age, or an empress regnant. The Kampaku (関白) was theoretically a sort of chief advisor for the Emperor, but was in practice the title of both first secretary and regent who assisted an adult emperor. The duties of the Sesshō and Kampaku were to convey to the Emperor the policies formulated by the Sadaijin (左大臣, Minister of the Left) and other senior officials of the Daijō-kan (太政官, Council of State), and to convey the Emperor's decisions to them. As regents of the Emperor, the Sesshō and Kampaku sometimes made decisions on behalf of the Emperor, but their positions were not defined by law and they had no specific political authority. The two titles were collectively known as sekkan (摂関), and the families that exclusively held the titles were called sekkan-ke (sekkan family).

During the Heian period (794–1185), from the middle of the 9th century, the Fujiwara clan began to marry off their daughters to the Emperor and assume the positions of Sesshō and Kampaku, thereby excluding other clans from the political centre and increasing their political power. From the 10th century, the Fujiwara clan monopolized the Sesshō and Kampaku, and at the end of the 10th century, around the time of Fujiwara no Michinaga and Fujiwara no Yorimichi, the power of the Fujiwara clan reached its zenith. In the mid-11th century, Emperor Go-Sanjo ran his own government, and the next Emperor, Shirakawa, abdicated to become Cloistered Emperor, beginning the cloistered rule. From then on, the cloistered rule of Cloistered Emperor took root, and the de facto Fujiwara regime, which used the positions of Sesshō and Kampaku, was over, and the Sesshō and Kampaku lost their real political power and became mere names.