The 1948 Arab–Israeli War, also known as the First Arab–Israeli War, followed the civil war in Mandatory Palestine as the second and final stage of the 1948 Palestine war. The civil war became a war of separate states with the Israeli Declaration of Independence on 14 May 1948, the end of the British Mandate for Palestine at midnight, and the entry of a military coalition of Arab states into the territory of Mandatory Palestine the following morning. The war formally ended with the 1949 Armistice Agreements which established the Green Line.

The 1948 Palestine war was fought in the territory of what had been, at the start of the war, British-ruled Mandatory Palestine. During the war, the British withdrew from Palestine, Zionist forces conquered territory and established the State of Israel, and over 700,000 Palestinians fled or were expelled. It was the first war of the Israeli–Palestinian conflict and the broader Arab–Israeli conflict.