Commagene was an ancient Greco-Iranian kingdom ruled by a Hellenized branch of the Orontids, a dynasty of Iranian origin, that had ruled over the Satrapy of Armenia. The kingdom was located in and around the ancient city of Samosata, which served as its capital. The Iron Age name of Samosata, Kummuh, probably gives its name to Commagene.
Commagene has been characterized as a "buffer state" between Armenia, Parthia, Syria, and Rome; culturally, it was correspondingly mixed. The kings of the Kingdom of Commagene claimed descent from Orontes with Darius I of Persia as their ancestor, by his marriage to Rhodogune, daughter of Artaxerxes II who had a family descent from king Darius I. The territory of Commagene corresponded roughly to the modern Turkish provinces of Adıyaman and northern Antep.
Wikipedia https://en.wikipedia.org/wiki/Kingdom_of_Commagene
Address 02000, Turkey
Coordinates 37°47'32.393" N 38°18'5.972" E