In 967 his father Murakami died and Reizei ascended to the throne at the age of eighteen and Sanetomo was appointed Kanpaku regend to support the emperor in his illness.
EmperorReizei (冷泉天皇 Reizei Tennō) (12 June950 - 21 November 1011) was the 63rd emperor of Japan (967 - 969), according to the traditional order of succession.
EmperorReizei was the second son of EmperorMurakami.
In 967 his father Murakami died and Reizei ascended to the throne at the age of eighteen and Sanetomo was appointed kanpaku regent to support the emperor in his illness.