Osprey's study of the first Persian invasion of Greece in 490 BC. The story of the Marathon campaign is an epic of the Ancient World. When the Ionian Greeks revolted against their Persian overlords in 499 BC, the cities of Athens and Eretria came to their aid. The Persian King Darius swore vengeance and in 490BC a fleet of 600 ships packed with troops was sent to take revenge on the Athenians. At Marathon the Greeks met the Persians in battle and drove them in rout back to their ships.The moral effect of this victory was enormous - for the first time a Greek army had defeated the Persians and demonstrated the superiority of hoplite tactics.