River, northwestern Jordan.
It rises in southwestern Syria and flows southwest to its confluence with the Jordan River . For most of its total course of about 50 mi (80 km), it forms the boundary between Syria and Jordan. A major battle along the river between invading Muslim Arabs and Byzantine forces in 636 AD established Muslim dominance in Palestine. That dominance, broken only by the period of the Crusades (1099–1291), lasted until World War I (1914–18). Since the Six-Day War of 1967, the lower river valley has been under Israeli control.