He was a grandson of a Shonagon (lesser councilor of state) SOGA no Yasumaro, who became the head of the Soga clan after the Jinshin War, and was a son of a Sangi (councillor) ISHIKAWA no Iwatari.
壬申の乱以降蘇我氏の嫡流となった少納言蘇我安麻呂の孫、参議石川石足の子。