The clan to which Iwatate originally belonged was named IWARE and its family name was SUGURI; however, the name of the clan was later changed to the SAKANOUE and its family name to KISUN.
はじめ氏を石村（いわれ）といい、姓（カバネ）は村主であったが、後に氏を坂上氏、姓を忌寸に改めた。