Tigris–Euphrates river system Tigris–Euphrates river system The Tigris and Euphrates, with their tributaries, form a major river system in Western Asia. From sources originating in eastern Turkey, they flow by/through Syria through Iraq into the Persian Gulf. The system is part of the Palearctic Tigris–Euphrates ecoregion, which includes Iraq and parts of Turkey, Syria, Iran, Saudi Arabia, Kuwait, and Jordan. From their sources and upper courses in the mountains of eastern Anatolia, the rivers descend through valleys and gorges to the uplands of Syria and northern Iraq and then to the alluvial plain of central Iraq. The rivers flow in a south-easterly direction
Khabur (Euphrates) it the "Aborrhas" (Ἀβόρρας), and Isidore of Charax called it the "Aburas" (Ἀβούρας). It was described as a large river of Mesopotamia which rose in Mons Masius, about from Nisibis, and flowed into the Euphrates at Circesium (Kerkesiah). Procopius speaks of it as a river of importance, and Ammianus states that Julian the Apostate crossed it “per navalem Aborae pontem.” Strabo describes it as near the town of Anthemusia. The river is fed by several smaller streams, the names of which are mentioned in the later classical writers. These are, the Scirtus (Procop. "de Aedif." 2.7), the Cordes (Procop. "de