An area in ancient Syria at the junction of the Taurus Mountains and the Euphrates River - a strategic position between the Roman and Parthian empires from which obsidian was exported from c 8000 BC. Commagene broke from the Seleucid Empire about 162 BC and its king, Antiochus I (c 69-34 BC) helped it rise in importance. Antiochus built his spectacular mausoleum on the peak of Nimrud Dag. Commagene was annexed by Rome in 17 AD and was later incorporated into the Roman province of Syria.