or Osrhoene
Ancient kingdom, northwestern Mesopotamia .
Located between the Euphrates rivers, it was situated across the modern frontier of Turkey and Syria, with its capital at Edessa (modern anlıurfa , Tur.). Founded in с 136 BC, it commanded strategic trade and military routes (1st century BC–2nd century AD). At different times it was allied with either {{link=Parthia">Parthia or Rome . The kingdom was abolished by the Roman emperor Caracalla in AD 216. In the 4th–7th centuries AD it was dominated by the wars between the Byzantine Empire and the Persian Sāsānian dynasty. Under various Arab dynasties, it became a centre of reaction against Hellenism and the headquarters of Chaldean Syriac literature and learning. It fell to the Muslims in 638.