The Settsu-Arima clan governing Arima County in Settsu Province, served as an attendant of the seii taishogun (literally, "great general who subdues the barbarians"), and directly belonged to the Muromachi shogunate independent of the Akamatsu clan, their head family.
摂津有馬氏は摂津国有馬郡を領して征夷大将軍の近習を務め、本家の赤松氏とは別に室町幕府に直勤していた。