The Merneptah Stele--First Historical Mention of the Name "Israel"
The Merneptah stele (a stone slab bearing an inscription) dating to the time of Pharaoh Merneptah (1224-1211 B.C.E.) contains the earliest historical reference to Israel in any source. This means that by the time of Merneptah, Israel existed as a nation, and the Exodus must have happened before this. The generally accepted date of Israel's exodus from Egypt is 1280 B.C.E.
Egypt Museum, Cairo