The Carthaginian Invasion of Greek Sicily of 481-480 BC took place at the same time as Xerxes's invasion of Greece and ended with a Greek victory at the battle of Himera.
Sicily at the time of this confict was split into several different communities. There were three different native groups, the Elymians and Sicanians in the west and the Sicels in the east.
In the north-western corner there were a number of Phoenician communities, the most important of which were Panormus, Motya and Soluntum. By 481 these cities were ruled from Carthage, the most important Phoenician city in the western Mediterranean. There is very little evidence of any earlier Carthaginian campaigns on Sicily, although there may have been a campaign in the middle of the previous century in which Carthage took control of the Phoenician cities.
Finally the island contained a number of powerful Greek cities. The older cities were on the eastern side of the island, but they had spread out and there were Greek cities at Selinus on the south-western coast and at Himera, just to the east of Soluntum.
The ancient sources contain two different reasons for the Carthaginian expedition. According to Diodorus the Persian king Xerxes sent an embassy to the Carthaginians in a successful attempt to convince them to attack the Greeks of Sicily at the same time as he attacked the Greeks of mainland Greece. The Carthaginians spent three years preparing for the invasion and raised an army of 300,000 infantry and a fleet of 200 warships. Mercenaries came from Italy, Liguria and Spain and other troops came from Libya and Carthage.
Herodotus tells a different story. Terillus, tyrant of Himera, had become a guest-friend of Hamilcar, the ruler of Carthage, a form of alliance. His daughter married Anaxilas, tyrant of Rhegium on the Italian mainland, another ally of Carthage. In c.482 BC Terillus was expelled from Himera by Theron of Akragas, on the southern side of the island. Terillus appealed to Carthage for help and Hamilar agreed to bring an army (also given as 300,000 strong) to Sicily.
The Carthaginian army landed at Panormus on the north-west coast of Sicily. He then advanced east and besieged Himera. Theron called for help from Gelon, who arrived at the head of 50,000 infantry and 5,000 cavalry (again probably an exaggerated figure). The combined Greek army challenged the Carthaginian army to battle, while the Greek cavalry launched a surprise attack on the Carthaginian naval camp on the coast. The resulting battle of Himera (480 BC) ended as a major Greek victory. Hamilcar was killed and most of his army destroyed.
In the aftermath of the battle Carthage sent ambassadors to Syracuse to negotiate a peace treaty. Gelon asked for 2,000 talents of silver and the construction of two temples each of which would house a copy of the treaty. One was probably built on the site of the battle of Himera, the location of the other is unknown. Over the next few decades the Carthaginians left Sicily alone and focused their effort on North Africa and Spain. They didn’t return to Sicily until 409 BC, but that began a long series of Carthaginian wars in Sicily.