Go-Sanjō (born Sept. 3, 1034, Kyōto—died June 15, 1073, Kyōto) was the 71st emperor of Japan, whose abdication in favour of his son, Kidahito (the emperor Shirakawa), established a precedent for government by retired emperor, thereby contributing to the decline of the powerful Fujiwara clan.
One of the few Japanese rulers of the period not born of a Fujiwara mother, Takahito became emperor in 1068, taking the reign name Go-Sanjo (Later Sanjo); he ascended the throne over the objections of the great clan, which, since 857, had dominated the government, usually by making Fujiwara daughters principal concubines or consorts to reigning emperors. A lack of daughters left the family vulnerable to Go-Sanjō, an emperor who chose to rule as well as to reign. Fujiwara dominance was further threatened when Go-Sanjō, seeking to reform court procedures and expenditures, established a records office (kirokujo) to scrutinize the legal titles of the great estates and confiscate those lacking authentic Imperial verification. Through claims to judicial and fiscal autonomy, these estates, some of the largest of which were owned by the Fujiwara, were wrecking the Imperial government. Even though the Fujiwara clan was torn by internal rivalries, they ignored most of Go-Sanjō’s directives, and his reform measures were largely unsuccessful.
In desperation, Go-Sanjō abdicated in favour of his son. Just as the Fujiwara had dominated the reigning emperors and grown rich and powerful through their daughters, Go-Sanjō and those who ruled after him for almost 100 years held power through their obedient sons.