An important river that rises in the mountains of Armenia and falls into the Persian Gulf, frequently called in scripture "the River." It provided a natural line of communication between east and west. It was the boundary of the land promised to the seed of Abraham (Gen. 15: 18; Deut. 1: 7; Josh. 1: 4; 1 Chr. 5: 9); this boundary was reached in the time of David (2 Sam. 8: 3; 1 Chr. 18: 3). The stronghold of Carchemish was built at the ford of the river, and was a position of great importance in military operations (2 Chr. 35: 20; Jer. 46: 2). On the banks of the Euphrates stood the great city of Babylon.