Genealogy
Before his ascension to the Chrysanthemum Throne, his personal name (his imina) was Takahira-shinnō (尊成親王?). He was also known as Takanari-shinnō
He was the fourth son of Emperor Takakura, and thus grandson of Emperor Go-Shirakawa. His mother was Bōmon Shokushi (坊門殖子) (Empress Dowager Shichijō-in, 七条院), daughter of Bōmon Nobutaka (坊門信隆) of the Fujiwara clan.
Read more about this topic: Emperor Go-Toba