Taira no Kiyomori
Takakura was the fourth son of Emperor Go-Shirakawa, and thus uncle to his predecessor, Emperor Rokujō. His mother was Empress Dowager Taira no Shigeko, the younger sister of Taira no Tokiko, the wife of Taira no Kiyomori. His empress consort was Taira no Tokuko (later Empress Dowager Kenrei), the daughter of Taira no Kiyomori, and thus his first cousin (as his mother and Tokuko's mothers were sisters).