In 499 BC, the Greeks of Ionia revolted against the Persian king Darius I, with help from Athens and Eretria. By 492 BC, the revolt had been suppressed. Darius then planned revenge on mainland Greece.
In 490 BC, the Persians invaded Greece by sea, sailing past Naxos and sacking Eretria in Euboea. Intending to attack Athens, they landed at Marathon, where they suffered a humiliating defeat. They retreated back to Asia.
In 480 BC, the Persians again invaded. At the pass of Thermopylae, their advance was checked by 300 Spartans who engaged the vast Persian army for many hours, dying to the last man.
The Persians then occupied Boeotia and Attica, sacking Athens. But the remaining Greek forces now inflicted a crushing defeat on Persian fleet at Salamis. The Persian king Xerxes retired to Asia with 60,000 men.
In 479 BC, a great Spartan and Athenian army annihilated the remaining Persian forces at Plataea. The Greeks then took the war to Asia, routing the Persian fleet off Mount Mycale and liberating much of Ionia.
