Tigris (Arabic: دجلة, Dijla, Turkish: Dicle) - The eastern member of the pair of great rivers that define Mesopotamia, along with the Euphrates, which flows from the mountains of Anatolia through Iraq. The river then merges with the Euphrates in southern Iraq to form the Shatt al-Arab, which in turn flows on into the Persian Gulf. Baghdad, the capital of Iraq, is on the western bank of the Tigris.