History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
and they still inhabit the western parts of Sicily. But on the capture of Ilium some of the Trojans, who had escaped the Achaeans, came in boats to Sicily, and settling on the borders of the Sicanians were called, as a people, Elymi, while their cities were named Eryx and Egesta. And there settled with them also some of the Phocians, who on their return at that time from Troy were driven by a storm first to Libya and thence to Sicily.
The Sicels, again, crossed over from Italy, where they dwelt, to Sicily, fleeing from the Opicans—as is probable and indeed is reported— on rafts, having waited for their passage till the wind was from the shore; or perhaps they sailed thither in some other way also. Even now there are Sicels still in Italy; and the country was named Italy after Italus, a king of the Sicels who had this name.