保元之亂
was the 77th emperor of Japan, according to the traditional order of succession. His de jure reign spanned the years from 1155 through 1158, though arguably he effectively maintained imperial power for almost thirty-seven years through the "insei" system - scholars differ as to whether his rule can be truly considered part of the "insei" system, given that the Hōgen Rebellion undermined the imperial position. However, it is broadly acknowledged that by politically outmaneuvering his opponents, he attained greater influence and power than the diminished authority of the emperor's position during this period would otherwise allow.