Ancient city of S Babylonia, in modern Iraq, 30 miles NW of An Nasiriyah. It was the biblical Ellasar (Gen. 14:1). When the last king of the third dynasty of Ur was overthrown (1950 B.C.) by the Elamites and Amorites, the cities of Isin and Larsa were rivals for hegemony in Mesopotamia. In 1763 B.C., Hammurabi defeated Larsa and succeeded in uniting Babylonia under his power. The city was dedicated to the sun god, Shamash. Temple libraries and important documents have been found in the ruins.