However, as the Southern House of the Fujiwara clan entered a terminal decline after FUJIWARA no Nakamaro's Rebellion, the Ishikawa clan also failed to produce other kugyo (court noble) succeeding ISHIKAWA no Mamori (Toshitari's grandchild and the seventh generation of Umako's grandchildren), who was Shoshiinojo (Senior Fourth Rank, Upper Grade) and sangi (Councillor), died after the transfer of the capital to the Heian-kyo, and would vanish from history.
しかし、その藤原南家が藤原仲麻呂の乱で衰退してしまうと、石川氏も平安京遷都後亡くなった正四位上・参議、石川真守（年足の孫、馬子の7代孫）を最後に公卿は出なくなり、歴史から姿を消した。