A decline in food production, the growth of the population, and competition for resources among the great families all led to the gradual decline of Fujiwara power and gave rise to military disturbances in the mid-tenth and eleventh centuries.
Members of the Fujiwara, Taira, and Minamoto families—all of whom have descended from the imperial family—attack one another, claim control over vast tracts of conquered land, set up rival regimes, and generally upset the peace.
The Fujiwara had controlled the throne until the reign of Emperor Go-Sanjō (1068-1073), the first emperor not born of a Fujiwara mother since the ninth century.
Go-Sanjo, determined to restore imperial control through strong personal rule, had implemented reforms to curb Fujiwara influence.
H had also established an office to compile and validate estate records with the aim of reasserting central control.
Many shōen were not properly certified, and large landholders, like the Fujiwara, feel threatened with the loss of their lands.
Go-Sanjo had also established the Incho, or Office of the Cloistered Emperor, which will be held by a succession of emperors who abdicate to devote themselves to behind-the-scenes governance, or insei.
The Incho has filled the void left by the decline of Fujiwara power.
Rather than being banished, the Fujiwara have mostly been retained in their old positions of civil dictator and minister of the center while being bypassed in decision making.
In time, many of the Fujiwara will be replaced, mostly by members of the rising Minamoto family.
While the Fujiwara fall into disputes among themselves and formed northern and southern factions, the insei system allows the paternal line of the imperial family to gain influence over the throne.
The period from 1086 to 1156 is the age of supremacy of the Incho and of the rise of the military class throughout the country.
Military might rather than civil authority dominates the government.
Minamoto no Yoshiie, named governor of Japan’s northern province of Mutsu in 1083, had taken it upon himself, without orders from the Imperial Court, to bring some peace and order to the region.
A series of disputes between Kiyohara no Masahira, Narihira, and Iehira over leadership of Mutsu’s Kiyowara cla had turned to violence.
Yoshiie intervenes in 1086 to stop the constant fighting between the leaders of the many Kiyohara branches, unsuccessfully besieging the fort where Iyehira and his Kiyowara rebels have withdrawn for the winter.
Intense cold and hunger decimates Yoshiie’s forces, forcing the survivors to retreat.
