In the 5th century BC the vast Persian Empire attempted to conquer Greece. If the Persians had succeeded, they would have set up local tyrants, called satraps, to rule Greece and would have crushed the first stirrings of democracy in Europe.
The survival of Greek culture and political ideals depended on the ability of the small, disunited Greek city-states to band together and defend themselves against Persia's overwhelming strength. The struggle, known in Western history as the Persian Wars, or Greco-Persian Wars, lasted 20 years--from 499 to 479 BC.
Persia already numbered among its conquests the Greek cities of Ionia in Asia Minor, where Greek civilization first flourished. The Persian Wars began when some of these cities revolted against Darius I, Persia's king, in 499 BC.
Athens sent 20 ships to aid the Ionians. Before the Persians crushed the revolt, the Greeks burned Sardis, capital of Lydia. Angered, Darius determined to conquer Athens and extend his empire westward beyond the Aegean Sea.
In 492 BC Darius gathered together a great military force and sent 600 ships across the Hellespont. A sudden storm wrecked half his fleet when it was rounding rocky Mount Athos on the Macedonian coast. Two years later Darius dispatched a new battle fleet of 600 triremes. This time his powerful galleys crossed the Aegean Sea without mishap and arrived safely off Attica, the part of Greece that surrounds the city of Athens.
The Persians landed on the plain of Marathon, about 25 miles (40 kilometers) from Athens. When the Athenians learned of their arrival, they sent a swift runner, Pheidippides, to ask Sparta for aid, but the Spartans, who were conducting a religious festival, could not march until the moon was full. Meanwhile the small Athenian army encamped in the foothills on the edge of the...