The Hot Gates

The Largest Army the World Had Ever Seen

In 480 BC, Xerxes I of Persia assembled the largest invasion force the ancient world had ever seen. Modern estimates put it at 120,000 to 300,000 soldiers — infantry, cavalry, archers, and the elite Immortals, his personal 10,000-man royal guard. The ancient Greeks claimed millions. Whatever the exact number, it was enormous — an army so large it supposedly drank rivers dry as it marched.

Xerxes had one goal: punish Greece for the humiliation his father Darius had suffered at Marathon ten years earlier, and absorb the fractious Greek city-states into the Persian Empire. He built a bridge of boats across the Hellespont (the Dardanelles) and marched his army from Asia into Europe. When a storm destroyed his first bridge, Xerxes had the sea whipped 300 times as punishment. He was not a man accustomed to being told no.

The Greeks knew he was coming. They had months of warning. The problem was that Greece wasn’t a country — it was a collection of fiercely independent city-states that hated each other almost as much as they hated the Persians. Getting them to cooperate was like herding cats with spears.

Sparta, the most feared military power in Greece, was willing to fight. But it was August, the time of both the Olympic Games and the Spartan religious festival of Carneia, during which Spartan law forbade large-scale military campaigns. King Leonidas I was authorized to take only his personal bodyguard — 300 hand-picked Spartan warriors, all of them fathers with living sons, so their family lines would survive if the mission failed.

Everyone understood what that meant.

The Pass

Thermopylae means “Hot Gates” — named for the hot springs near the narrow coastal pass in central Greece. In 480 BC, the pass was a strip of land barely wide enough for a single wagon, squeezed between the mountains and the sea. Today the coastline has shifted and the pass is miles from the water, but in antiquity it was a natural chokepoint — the only road a large army could use to march south toward Athens.

Leonidas arrived with his 300 Spartans and picked up allies along the way: 700 Thespians, 400 Thebans, and several thousand other Greeks from various city-states. Total Greek force: approximately 7,000 men.

They rebuilt an ancient stone wall across the narrowest part of the pass — the “Middle Gate” — and waited. The terrain made the Persian numerical advantage meaningless. In the narrow pass, Xerxes could only send a few thousand men at a time. The rest of his army was useless, stacked up for miles behind the front.

Xerxes sent a messenger to Leonidas demanding the Greeks surrender their weapons. Leonidas reportedly sent back two words: “Molon labe” — “Come and take them.”

Day One & Day Two

On the first day, Xerxes sent his Median and Cissian infantry — good troops, but not his best. They charged into the pass in waves and were slaughtered. The narrow ground meant only a handful of Persians could engage the Greek line at once, and the Greeks — especially the Spartans — were better armored, better trained, and fighting in a disciplined phalanx formation that turned the pass into a meat grinder.

The Spartans used a devastating tactic: they would present their shield wall, engage the Persians, then feign a retreat. The Persians would charge forward in disorder, and the Spartans would wheel around in perfect formation and cut them to pieces. They did this over and over. The Persians died in heaps.

According to Herodotus, Xerxes watched from his throne on a nearby hill. He leapt to his feet three times in horror as he watched his men get butchered.

On the second day, Xerxes sent the Immortals — his elite guard, 10,000 of the best soldiers in the Persian Empire. The result was the same. The Immortals were superb troops in open battle, but in the pass they couldn’t use their numbers, their mobility, or their archery effectively. The Spartans cut them down like the rest.

By the end of Day Two, Xerxes had lost an estimated 10,000 to 20,000 men. The Greeks had lost perhaps a few hundred. The pass held.

The Betrayal

On the night of the second day, a local Greek named Ephialtes came to Xerxes with information that changed everything: there was a hidden mountain path — the Anopaea trail — that led behind the Greek position. For a reward, Ephialtes offered to guide the Persians through it.

Xerxes sent Hydarnes and the Immortals up the mountain path that night. The trail was guarded by 1,000 Phocian Greeks, but when they heard the Persians approaching at dawn, the Phocians retreated to higher ground rather than fighting. The Immortals ignored them and kept marching.

Leonidas received word of the betrayal at dawn on the third day. He now knew his position was untenable — the Persians would emerge behind him within hours. He was surrounded.

Leonidas made his decision: dismiss the bulk of the Greek army so they could fight another day. He would stay at the pass with his 300 Spartans, 700 Thespians who refused to leave, and 400 Thebans as a rear guard to cover the retreat.

When asked why, Leonidas reportedly said that it was not the Spartan way to abandon a defensive position. Sparta had sent him to hold the pass. He would hold it.

The Last Stand

On the morning of Day Three, Leonidas and his remaining force advanced out of the pass for the first time. They weren’t defending anymore. They were attacking.

The Greeks pushed deep into the Persian ranks, killing enormous numbers. Leonidas knew he was going to die — they all knew — and they fought with the furious abandon of men with nothing left to lose. Two of Xerxes’ own brothers, Abrocomes and Hyperanthes, were killed in the fighting.

Leonidas fell. The fighting over his body was savage — the Spartans drove the Persians back four times to protect their king’s corpse. They recovered his body and formed a defensive circle on a small hill near the wall.

By now their spears were broken. They fought with swords. When the swords broke, they fought with daggers and their bare hands. Herodotus writes that some fought with their teeth.

The Immortals arrived from the mountain path behind them. The Greeks were now surrounded on all sides. Xerxes, tired of losing men, ordered his archers to finish it. The Persians stood at a distance and poured arrows into the remaining Greeks until the last man fell.

The Thebans, it should be noted, surrendered. The Spartans and Thespians did not. They died to the last man.

Why It Matters

Thermopylae was a defeat. The pass fell. The Persians marched south and burned Athens. In purely military terms, the battle changed nothing.

In every other term, it changed everything.

The three-day delay at Thermopylae bought the Greek fleet time to prepare for the Battle of Salamis, where Themistocles destroyed the Persian navy. Without Salamis, Greece falls. Without Thermopylae, there is no Salamis.

But the real legacy is what the stand meant. Three hundred men — who knew they were going to die, who could have retreated with honor — chose to stay because their duty required it. They fought an empire to a standstill in a mountain pass for three days, killing thousands, and died rather than yield.

The epitaph at Thermopylae, written by the poet Simonides, became the most famous memorial in the ancient world: “Go tell the Spartans, stranger passing by, that here obedient to their laws we lie.”

2,500 years later, people still visit the site. There is still a monument. The words are still carved in stone. Leonidas and his 300 became the archetype of the last stand — the idea that some positions are worth holding no matter the cost, that courage in the face of certain death is not pointless but sacred.

Every last stand since — the Alamo, Rorke’s Drift, Wake Island, Bastogne — lives in the shadow of Thermopylae.