According to the "Ishibashi Clan Family Tree" handed down to Dr 石橋正良 of Yame City, Fukuoka Prefecture, the Ishibashi clan in the Yame region started when Uemon-morikiyo ISHIBASHI (died in 1601), a senior vassal of the lord of the Shimoda-jo Castle of the Chikugo Province 堤貞元 who was a Seiwa Genji-lined samurai from Hizen Province and a family member of the Otomo clan of the Bungo Province, settled in Hoshino-mura village, Ikuha County, Chikugo Province in a certain point of the Tensho era (1573 - 1593).
福岡県八女市の医師石橋正良宅に伝わる『石橋氏系図』によると、八女地方の石橋一族は、清和源氏の血を引く肥前出身の武士で豊後大友氏の門族である筑後国下田城主堤貞元の重臣石橋右衛門盛清（慶長6年没）が天正年間（1573年から1593年）に、筑後国生葉郡星野村に定住したのがはじまりである。