In and after the late medieval period, Shonagon was known as the official position appointed to the court nobles from the Funabashi family in the Kiyohara clan line, after having served as a tutor to the emperor.
中世後期以後は、清原氏系の舟橋家の公卿が天皇の侍読を経た後に任じられる官職として知られていた。