The Persian Wars were fought between Persia and independent Greek city-states in the first quarter of the 5th century BC. Most of our knowledge about the wars comes from the Histories of Herodotus. The wars were decisively won by the Greek cities, who for the first time united behind their cultural and racial ties. The Greek unity was brief (by the end of the century Sparta had humbled Athens in the Peloponnesian War) and shallow (only 30-40 of the hundreds of Greek cities fought against Persia). Still pride and ideals of valor and service to one's city diffused throughout the Greek world.
By the turn of the 5th century the vast Persian Empire stretched to the northwest coast of the Aegean Sea. Persia had loose control of the prosperous Ionian (eastern Aegean) cities founded by the Greeks, relying on local tyrants to ensure the flow of taxes to central Persia. The Ionians got sick of the imperialism and banded together against Persia. They requested assistance from mainland Greek cities. In 498 Athens and Eretria sent 25 ships across the Aegean. The Ionians and their enlisted help moved inland and set fire to the city of Sardis, sparking revolts in other Greek cities of Asia Minor. The Persians subdued the insurrections and turned their attentions to mainland Greece.
The Persian ruler Darius sent hundreds of triremes across the Aegean. His forces attacked and won control of the island of Naxos and the city Eretria on Euboea. They moved from Euboea to mainland Greece, landing at Marathon, 42 km north of Athens. The Athenian army met the Persians at Marathon and, though outnumbered two to one, decimated them. Over 6,000 Persians and only 192 Greeks died in the battle. Legend has it that a messenger Phidippides ran back to Athens to announce the victory. In memorial the marathon run of 42 km was introduced to the Olympic games of Athens in 1896.
After the death of Darius, his more ambitious son Xerxes planned and launched a huge attack against Greece. Xerxes oversaw the digging of canals for safe ship passage and the construction of pontoon bridges across the Hellespont for passage of troops and horses. He sent hundreds of thousands of troops and 600 triremes along the edge of the Aegean Sea toward Greece in 481 BC. The Greek cities had no choice but to coalesce against such a massive force. A coalition of thirty cities agreed to make Sparta the commander of the Greek army and navy.
The Greeks decided to meet the Persian fleet at the northern tip of Euboea. Athens sent 200 ships and Peloponnesian cities sent 70. The Greeks met the Persian army at Thermopylae. The Persian army easily overwhelmed the resistance at Thermopylae but its navy was nowhere near as fortunate. 200 Persian ships were lost in a storm at Euboea and the naval battle was inconclusive. The Persian army moved south and the Greek army fortified the isthmus between Attica and Peloponnesia. The Greek navy retreated to the island Salamis near the isthmus. This left Athens defenseless, and the Persians plundered and set fire to it.
Xerxes decided to confront the Greek navy at Salamis. The Greeks were in deep trouble and had to rely on cunning. One Athenian leader Themistocles sent Xerxes a slave with news that the Greek navy was in disarray and was planning an escape attempt. Themistocles hoped Xerxes would hastily attack, which he did. The Greeks battered the Persians in the naval battle at Salamis. Perhaps 200 Persian ships were lost, compared to 40 Greek ships. The Persian navy, along with Xerxes, returned to the eastern Aegean. Xerxes left his army under the control of the general Mardonius. Herodotus considered the Battle of Salamis to be the decisive moment in the Persian Wars. Soon afterward the Greeks, led by the Spartans, defeated Mardonius and his army at Plataea. The Persian Wars were effectively over, allowing the Greek cities to focus their hostilities on each other.