Xerxes I, king of Persia, planned for years his campaign against the Greek city-states to avenge their defeat of his father, Darius I, at Marathon in 490 BC. Part of his preparation included enlisting Carthage, on the north coast of Africa, to invade Sicily, thereby pinning down the forces of Syracuse and Agrigento and preventing their coming to the defense of their fellow Greeks on the mainland.

In 480 BC Xerxes launched his long-awaited attack against the mainland Greeks. At the same time his Carthaginian allies began their invasion of Sicily. At Himera, on the north coast of Sicily, the Carthaginians met devastating defeat at the hands of Syracuse, aided by the forces of Agrigento. Thereafter, with the external threat repulsed, Gelon, Tyrant of Syracuse, consolidated his power throughout most of Greek Sicily.

Xerxes fared no better than his Carthaginian allies. After a series of Persian victories in preliminary naval engagements and a costly victory over the Spartans on land at Thermopylae, the Persian and Athenian fleets met each other at Salamis in one of history's most celebrated sea battles. The result was punishing defeat for the Persians, who lost half their entire fleet. The united Greek armies followed up on that triumph with land victories at Plataea and Mycale, paving the way for a Greek cultural heritage in Europe rather than a Persian one.