TIGRIS, the eastern river of ancient Iraq, which together with the Euphrates formed the alluvial plain of Mesopotamia, “The Land of the Two Rivers.” The Tigris arises in the Zagros mountains of western Kurdistan and flows with many tributaries such as the Greater and Lesser Zab and the Diyala, from NW to SE some 700 m. until it empties into the Persian Gulf. It was for centuries the easternmost boundary of the Sumer. peoples and the meeting place of Elamite, Indo-European and Sumer. The snows of the Zagros melt and flow S causing the Tigris to reach full flood stage in May and June. The mysterious “protoeuphratean” peoples, whose character is only vaguely known, apparently named the stream. The name Idiglat, which they used, was handed down by the Sumerians and later Babylonians for millennia.

The overall length of the Tigris, nearly 1200 m. in all, was dotted in antiquity by the towns of many lost civilizations. In the far N lived the Urartu who lent their name to Mt. Ararat, the Cimmerians and centuries later the Guti. In the foothills of the Zagros are the remains of such ancient pre-neolithic sites as S̆anidar and Tepe Gawra, while the Sumerians built Ešnunna, Lagaš and the towns which once flourished at the sites of Samarra and Khafaje. The S became dominated after the end of the third millennium by the Sem. Akkadians and their rulers of Sumer and Agade. In the northern reaches the Assyrian empire arose. Their capital cities of Nineveh, Aššur and Nimrud are located on its banks. The plain between the northern reaches of the Tigris and Euphrates which was settled by the Aramaeans and called by the psalmist, Aram Naḥaraim (Ps 60:1 KJV) “Aram by (the) twin rivers,” this name was used in later times for other parts of the Iraqi water shed. The ancient alterations of the course of the Tigris are as yet imperfectly understood and work of surface surveying has been going on for many years. It is known that in recorded history these rivers changed channels more than once, often leaving once verdant marshes and grass lands to become parched deserts. The long caravan route from North India which crossed over to the Syro-Palestinian coast followed the course of the Tigris for hundreds of m., finally veering off toward the Euphrates at Nineveh, a reason for that city’s great wealth and power. The difficulty of the terrain, the harshness of the climate and the capricious nature of the water supply, demanded close knit and elaborate social systems for men to survive, and for townships to flourish on the banks of the Tigris. Perhaps this inhospitable topography more than any other factor encouraged the rise of Mesopotamian civilization.