SHIRAKAWA was the first son of Emperor Go-Sanjo who had little maternal relationship with the Fujiwara Five Regent Houses, and his mother, Nyogo, FUJIWARA no Moshi/Shigeko was from Fujiwara Kaninryu, the daughter of Chunagon FUJIWARA no Kinnari, and the adopted daughter of Togu Daibu FUJIWARA no Yoshinobu.
藤原氏摂家と外戚関係の薄い後三条天皇の第一皇子として生まれ、母は藤原氏閑院流出身で中納言藤原公成の娘、春宮大夫藤原能信の養女である女御藤原茂子（?-1062）。