The Greco-Persian Wars refers to a series of wars between the various city-states of Greece and the Persian Empire between 492 and 449 BC (though some historians put the earlier date at 499, at the beginning of the Ionian revolt), during which the Greeks triumphed over what appeared to be insurmountable numerical odds to drive out the invading Persians. However, the origins of enmity between Greece and Persia go back half a century further.
The Beginning of Greco-Persian Conflict
In 546 BC, the Persian Emperor Cyrus, who called himself "the King of Kings," expanded his empire to include the Anatolian coast of Greece. Only the Lydians under Croesus offered any serious resistance, and even they were easily crushed by the superior numbers of the Persians. Perhaps the most well-remembered event of this time occurred when the Spartans sent a missive to Cyrus warning him to stay away from the rest of Greece or risk their intervention, prompting Cyrus to wonder aloud, "Who are the Spartans?"
The Ionian Revolt
By 499 BC, all the ethnic Greek people of Asia Minor, known as the Ionian Greeks, were under Persian rule. At this time, Aristagorus, the Persian-appointed tyrant of the Ionian island Miletus, led a campaign on behalf of Persia to conquer the island of Naxos. The effort failed miserably. The Persian Emperor Darius the Great (who ascended the throne upon Cyrus' death in 522), not used to or fond of losing, promptly informed Aristagorus he needed to find a new occupation, as he was hereby dismissed from his previous position as ruler of Miletus.
Infuriated, Aristagorus incited the entire west coast of Anatolia to rise up in rebellion against Persia, taking advantage of the population's long-standing resentment of the oppressive conditions imposed by Persian-backed tyrants such as himself. The ensuing conflict, known as the Ionian Revolt, began in 499 and lasted until 493, when the Ionian rebels were finally defeated. During the revolt, the Ionians secured help from Athens and Eretria, who sent a small combined fleet that helped the Ionians briefly capture the Persian regional capital of Sardis and burn it to the ground in 498. The conflict proved a stalemate until 494, when Darius sent significant reinforcements to the Persian forces. The exhausted Ionians were soon defeated, losing the last of their leadership at the Battle of Lade. The following year consisted of vast Persian forces mopping up isolated pockets of Ionian resistance.
The Invasion Begins
Darius was incensed at the Ionian revolt, and even more angry that the Greeks of Athens and Eretria had dared aide the rebels. He vowed to punish not only Athens and Eretria, but the whole of Greece, which he intended to add to his empire. Thus far, no enemy had successfully resisted the full might of the Persians.
In 492 BC, the Persian general Mardonius swept into Thrace and Macedonia, easily overwhelming the outclassed Thracians and the valiant but incredibly disorganized Macedonians. Following this easy triumph for the invaders, there was a brief pause as the Persians regrouped and prepared their next move after losing almost an entire invasion fleet during a storm.
The Battle of Marathon
By 490 BC, the Persians were ready to launch another wave of attackers at Greece. After their navy easily subjugated the Cyclades, the Persian military turned its sights on Eretria. Following a brief siege, Eretria was not only defeated but destroyed, suffering the same fate as Sardis but on a larger scale. With one of the two cities that had aided the Ionians successfully punished, Persia turned its attention to Athens with a two-pronged assault.
First, a vast army of 25,000 men, including 5,000 cavalry, landed unopposed at the bay of Marathon, a perfect staging ground from which to march on Athens in earnest. Meanwhile, a second, smaller force headed toward Athens from further away to provide reinforcements and cut off aide in the event of a siege, or to sack the city should the Athenians leave it undefended to meet the main Persian force.
The Athenians, possessing an army of only 10,000, none of which included cavalry, sent to Sparta for aid, appealing to the Spartan's self-interest. Surely the Spartans could see the two cities stood a much better chance against the Persians if they combined their forces than Sparta did on its own? The Spartans agreed to help, but only after the conclusion of one of their major religious festivals.
The Athenians had two choices: They could try to survive a siege better than the Eritrians had managed while hoping the Spartans showed up, with even the best case scenario leading to utter devastation in the surrounding countryside. Or they could carry the fight to one group of Persians, leaving Athens undefended behind them.
Ten thousand Athenians led by ten generals, chief among them Miltiades, marched toward the Plain of Marathon, picking up one thousand warriors from Plataea along the way. Arriving at Marathon, Miltiades left some troops behind to cut off the exits to the plain, and then drove his army straight at the larger Persian force. Persian arrows proved ineffective against the heavily armored hoplite troops of the Greeks, and when the two forces met in close combat, the Persians, who had yet to face a disciplined Greek fighting force, had no plans for how their lightly armored troops were supposed to defeat heavily armored warriors fighting in concert with each other. Rather than use their speed to harry the hoplites, the Persians met the Greeks head on. The Athenians devastated their foes, taking only 192 casualties while killing 6400 Persians, according to the historian Herodotus.
But the Greeks were in no position to celebrate their impressive victory. As soon as the Persians had retreated aboard their ships and begun to sail away, the Athenian army began the second half of one of the most amazing feats in military history. They immediately turned around and marched back to Athens, arriving just in time to stop the second Persian force from securing a foothold near the city. With the advantage lost and outnumbered in hostile territory, the Persian commander quickly retreated, and the Persian forces sailed home.
For the first time, the Greeks--or, to be precise, the Athenians, fighting almost alone--had defeated the Persians.
Intermission, or, The Great Naval Build-Up
Darius quickly made plans to launch another invasion with even more troops, but while the build-up was underway, Egypt revolted. Darius himself died before Persia could march on Egypt, and the his son Xerxes put down the rebellion instead. Afterwards, Xerxes began preparing to avenge his father's defeat in Greece, building a bridge to allow for a massive land invasion and a canal with which to launch the largest fleet of ships the world had yet seen. By 481, his preparations were complete.
But the Greeks had not been entirely idle during this time. Miltiades had died of a wound received in battle, but Themistocles, the most influential Athenian statesman and a canny general in his own right, had long urged a build-up in Athenian naval power. While he usually made reference to other priorities as a pretext, he was almost certainly planning ahead for a possible future war against the naval might of the Persians. When a giant vein of silver ore was discovered near Athens in 483, he successfully insisted the profits be put into building a fleet of 200 Athenian warships. Meanwhile, the Persian build-up had not gone unnoticed in Greece. In 481, a league of Greek states was formed to oppose Persia. The united Greeks gave the Athenian forces command over the navy and the Spartans command of the army.
War Begins, Again
In 480, the massive Persian forces made their way to Greece. Herodotus estimated the Persian army to number 2.5 million, and other Greek accounts claimed similar numbers, but modern historians have concluded these were exaggerations, intentional or not, and the largest force logistically possible for the Persians to launch at the time would have been 150,0000 to 200,000 men, with a fleet generally estimated at around 1200 ships. Meanwhile, the giant 200 ship build-up in Athens had elevated the Greek total to approximately 350 ships.
Themistocles proposed a strategy where the Greeks would make their principle stands at the pass of Thermopylae on land and Artemisium at sea.
At the very narrow pass of Thermopylae, 7,000 Greek troops under the command of the Spartan general Leonidas successfully fought off a force well over ten times their number for two days in August of 480, handing the Persians heavy losses. Then a local traitor named Ephialtes showed the Persians a mountain path that led around the pass, and the Persians sent a force including the 10,000 elite troops known as "the Immortals" around behind the main Greek army.
Realizing the position had become hopeless, Leonidas sent most of Greek forces to safety, remaining behind with 300 elite Spartan troops and a few other Greek soldiers. On the third day, as the Persians marched through the pass, the remaining Greeks left their fortified position to try and slow the Persian advance, trying to inflict as much damage on the enemy as possible before finally succumbing to the many tens of thousands arrayed against them.
After Thermopylae, the Persian Army poured through Greece, meeting no serious opposition and reaching Athens in September. The city had already been evacuated, but the Persians still set it aflame.
Also in mid-August, 200 Persian ships attempted to surprise the principle Greek fleet of 271 triremes, but the Greeks evaded them and attacked the main Persian force. After a day of furious fighting during which both sides suffered heavy casualties, the Greeks saw bad weather coming and put into port. Many of the Persian ships were destroyed during the storm, but they retained a huge advantage. The Greek fleet retreated, having neither won nor suffered a devastating loss.
When the Persian navy came to destroy the remaining Greek fleet at Salamis--a location chosen by the Greeks due to its narrow straits and the inability of the Persians to outflank them there--the Persians wisely refused to enter. Themistocles, in charge of the Greeks, quickly sent a series of false communications, designed to be intercepted by the Persians, stating that he was preparing a retreat. When his ships turned and fled, the Persians followed into the straight. Themistocles then reversed course and engaged, taking the Persian fleet by surprise and quickly destroying over 200 ships while taking minimal Greek casualties.
The Final Stages
Having lost the greater part of their fleet, the remaining Persian navy retreated. The Greek navy now controlled the ability of the Persians to resupply their massive army. Still, the Persians held a huge land superiority over the Greeks, and old Greek rivalries began to resurface, as the Spartans returned home and left the remainder of the fighting to Athens. Many other Greek cities joined the Spartans in returning home with fighting still to be done.
The Athenian forces remained in the field, but there simply weren't enough Athenians. After Athens was retaken and looted by the Persians yet again, the Athenian military announced they would make peace with the Persians unless aid was forthcoming.
Quickly, a huge Spartan-led contingent of Greek troops descended on the Persian army. Despite this new resolve, the war's outcome was still very much in doubt until the Persian general Mardonius was killed. No other commander of equal quality rose to take his place, and the Persians were soon in full retreat. The final major engagement occurred at Palataea, where a combined force of Athenians, Spartans and Tegeans trounced the remaining Persians. The final naval battle, a resounding triumph for the Greeks at Mycale, was almost an afterthought, as the Persians retreated with barely a fight.
The Peace of Callias
The Greeks and Persians continued to skirmish for another 30 years, as the Athenians led an offensive to liberate the Ionian Greeks. Neither side ever fully triumphed, nor were any of the battles on the scale of those during the Persian invasions. Finally, in 449 BC, a truce called the Peace of Callias ended the hostilities between the Greeks and Persia.