King Arsames, who ruled (part of) Armenia, is known from the inscriptions, found on Nemrud Dagi, in which king Antiochus I Theos of Commagene mentions his ancestors. Arsames must be dated in the third quarter of the third century BCE. If this date is correct, he may have benefited from the weakening of the nearby Seleucid Empire during the Third Syrian War (246-241) and may have expanded his influence.
Arsames is associated with the founding of three cities in the southwest of Greater Armenia: in Sophene, he built Arsamosata (near modern Elazığ), and in Commagene, he built Arsameia on the Euphrates (Gerger) and Arsameia on the Nymphaeus (Eski Kale).
He is probably the Arsames who in 227 BCE offered asylum to Antiochus Hierax, a Seleucid rebel prince.note[Polyaenus, Stratagems 4.17.]