In winter, on your soft couch by the fire, full of food, drinking sweet wine and cracking nuts, say this to the chance traveler at your door: 'What is your name, my good friend? Where do you live? How many years can you number? How old were you when the Persians came...?— Xenophanes
To the Greeks, there was one defining event in their history: the Persian Wars. Even today, we see a good deal of truth in this assessment, for the Greek victory in the Persian Wars triggered the building of the Athenian navy, which led to the Athenian Empire, the expansion of the concept of democracy, and the means to develop Greek civilization to its height.
Two main factors led to the Persian Wars. First, there was Persian expansion into Western Asia Minor, (bringing Ionian Greeks under their control) and into Thrace on the European side of the Aegean in search of gold. Second, Solon's reforms and Peisistratus’ seizing control of Sigeum had made Athens especially sensitive to any threats to its grain route from the Black Sea. Further complicating this was the fact that several Athenian nobles held lands in the North Aegean. The spark igniting this into war with Persian was a revolt of the Ionian Greeks.
The Ionian Greeks had peacefully submitted to Persian rule and lived under Persian appointed Greek tyrants since the time of Cyrus the Great. Then in 5l0 B.C.E., the Ionian Greeks raised the standard of revolt and drove their tyrants out. Realizing they needed help against the mighty Great King, Darius, they appealed to their cousins across the Aegean for aid. Sparta, ever wary of a Helot revolt, refused to help. However, Athens and another city-state, Eretria, did send ships and troops who joined the Ionians, marched inland, and burned the provincial capital, Sardis, to the ground. After a Persian force defeated the Greeks as they were returning from Sardis, the Ionian Greeks decided to stake everything on a naval battle at Lade (494 B.C.E.). Unfortunately, the combination of disunity in their ranks and Persian promises of leniency caused the naval squadron of one polis after another to defect to the Persians and Ionian resistance to collapse. Miletus, leader of the revolt was sacked and the rest of Ionia fell back under Persian sway.
The Athenians and Eretrians had eluded the Ionian disaster, but not Darius' notice. After finding out who the Athenians were, Darius supposedly appointed a slave to remind him of them daily until he had punished them. In 492 B.C.E., an expedition set sail, but much of it was shipwrecked off the coast of Thrace and the rest of it was forced to return home. Nothing daunted, Darius prepared another invasion force which set out in 490 B.C.E.. Persian ambassadors had preceded the army to demand earth and water as signs of submission from all the Greeks. Most gave in rather than face the might of the Great King. However, the Athenians supposedly threw them into a pit and told them to take as much earth as they wanted, while the Spartans, equally defiant, gave them their water by throwing them into a well.
Later that year, a Persian force of some 20,000 men landed at Marathon in Attica. Unfortunately, the Spartans, being as superstitious as they were defiant, could not march before the end of a festival on the full moon. Thus the Athenians were left to face the might of Persia all alone, or nearly alone, since the tiny city-state of Plataea sent its army of 1000 men to stand bravely by Athens. The Greeks still faced an army twice as numerous as their own and reputedly invincible in battle. Therefore, they did the last thing the lightly clad and overconfident Persians expected: they charged. The Persians hardly had time to unleash a volley of arrows before the Greeks were upon them. The shock of this human tank of heavily armored Greek hoplites crashing into their lines sent them reeling back and scurrying for their ships. The Persian fleet made a quick dash for defenseless Athens, only to find the Athenians had doubled back to meet them. Having lost their stomach for anymore fighting, they sailed for home.
The Athenians and other Greeks knew they had little cause for celebration, for the Persians would surely be back. It took ten years for the next invasion to materialize, because Egypt rebelled, as usual, and then Darius died. His son and successor, Xerxes, needed a decade to set his house in order and create a new army to invade Greece. Hoping to crush the Greeks by weight of numbers, this new army was nearly ten times as big as the one that lost at Marathon. Greek preparations were more thorough this time. For one thing, many, although by no means all, the city-states banded together in a defensive league with Sparta as its leader. The Athenians let their leader, Themistocles convince them to use the extra money from a large lode of silver found at Laurium in Attica to pay for a larger fleet, believing sea power would be the key to victory.
The Greeks sent an advance force of some 7000 Greeks under the Spartan king Leonidas to hold the narrow pass of Thermopylae in northern Greece. Nearby was a Greek fleet holding the narrow straits of Artemesium. Fighting in such narrow spaces would prevent the Persians from using their superior numbers to advantage. For several days, the Greeks, led by the Spartans, severely repulsed any Persian assaults at Thermopylae and threatened to stall Xerxes' whole invasion. Unfortunately, treachery accomplished what frontal assaults could not, for a local shepherd showed the Persians another path behind the Greeks. Before the trap was closed, most of the Greeks escaped. However, Leonidas and his picked guard of 300 Spartans along with 700 troops from Thespis chose to stay and fought to the last man, selling their lives dearly in the process. When Thermopylae fell, the Greek fleet defending nearby Artemesium had to retreat after some hard fighting.
As the Persian multitude spread southward, city after city surrendered or was abandoned, until the Peloponnesus was about the only part of Greece left free. Even the Athenians had to evacuate their population to the nearby island of Salamis and watch their city go up in flames as they waited for the decisive battle to decide the issue. That battle took place at sea in the strait of water between Salamis and Attica. The Greeks, under the leadership of the Athenian Themistocles, lured the Persians into the narrows where they were ambushed, crushed together so they could not maneuver, and destroyed ship by ship. This victory proved decisive enough to convince Xerxes to go home, leaving part of his army to finish the job.
However, it was the Greeks who would finish the job. First they crushed the Persian army at Plataea in 479 B.C.E., with the Spartans carrying off the honors for valor, to no one's surprise. Then the remainder of the Persian fleet was caught and destroyed at Mycale. This led to another, more successful Ionian revolt, so the Ionians were finally free. It also left the way open for the Greeks to destroy the bridge of boats that the Persians had used to cross the Hellespont from Asia into Europe. The destruction of that bridge signaled the end of the Persian wars, although no one at that time could assume the Persians would not come back.
We can well imagine the Greeks' incredible feelings of pride and accomplishment in 478 B.C.E. after defeating the Persian Empire. The Athenians felt that they in particular had done more than their part with their army at Marathon and their navy at Salamis and Mycale. It was this incredible victory which gave them the self-confidence and drive to lead Greece in its political and cultural golden age for the next half century.
However, victory had been won at a heavy price. Fields, orchards, and vineyards lay devastated throughout much of Greece, and it would take decades for the vineyards and olive groves in particular to be restored. Athens itself was in ruins, being burned by the Persians in vengeance for the destruction of Sardis during the Ionian Revolt. Therefore, the Athenians immediately set to work to rebuild their city, and in particular its fortifications. The Spartans, probably through fear or jealousy of Athens' growing power, tried to convince the Athenians not to rebuild their walls. They said that if the Persians came back and recaptured Athens, they could use it as a fortified base against other Greeks. The Athenian leader, Themistocles, stalled the Spartans on the issue until his fellow Athenians had enough time to erect defensible fortifications. (This was later extended by what was known as the Long Walls to connect Athens to it port, Piraeus, so it could not be cut off from its fleet.) By the time Sparta realized what was happening, it was too late to do anything. One could already see bad relations starting to emerge between Athens and Sparta. In time, they would get much worse.
Since the Athenians and other Greeks could not assume that the Persians would not come back, they decided the best defense was a good offense, and formed an alliance known as the Delian League. The League's main goals were to liberate the Ionian Greeks from Persian rule and to safeguard the islands in the Aegean from further Persian aggression. The key to doing this was sea power, and that made Athens the natural leader, since it had by far the largest navy and also the incentive to strike back at Persia. At first, Sparta had been offered leadership in the league because of its military reputation. However, constant fear of Helot revolts made the Spartans reluctant to commit themselves overseas. Also, their king, Pausanias, had angered the other Greeks by showing that typical Spartan lust for gold. As a result, he was recalled, leaving Athens to lead the way.
The Persian navy, or what was left of it, was in no shape to halt the Greek advance after taking two serious beatings from the Greeks in the recent war. Ionia was stripped from the Great King's grasp, and the Persians were swept from the Aegean sea island by island. Within a few years, the Delian League controlled virtually all the Greeks in the islands and coastal regions of the Aegean.