Battle of Thermopylae: Sparta’s Last Stand That Ended In The Most Upsetting Defeat

Greater equipped and prepared Spartans defeated in an outnumbered Battle of Thermopylae by Persians cause of upsetting betrayal from one of their own.

Western Democracy traces its roots to ancient Greece, a land of squabbling city-states. Amongst these warring city-states arose Athens, and a group of men who had a funny idea: citizens should get a say in who exactly got to rule them.

Though initially imperfect in its implementation, that idea has since evolved to the free Democratic nations most of us live in today- but fortunately, it wasn’t lost to one single moment in history, and that is the cause of a single important battle, the Battle of Thermopylae.

Persian invasions of Greece

Map showing the Greek world during the Greco-Persian Wars (ca. 500–479 BC), by Bibi Saint-Pol, CC BY-SA 3.0, via Wikimedia Commons

In 499 BC Greek cities which had been captured by the Persians in Asia Minor revolted against the brutal tyrants that had been placed to oversee them. In support of their conquered brethren, Athens and Eretria sent troops. Despite some major gains, several strategic mistakes cost the Greeks of Asia Minor their ultimate victory and the rebellion was put down.


With Asia Minor back in the fold of the Persian Empire, the Persian king Darius I vowed to punish Athens and Eretria for their involvement, and saw the rest of the free cities of Greece as a threat to his empire.

In 492 BC he launched an invasion of Thrace and Macedon, then sent heralds to the remaining Greek city-states demanding they accept Persian rule. Seeking to save themselves, many agreed- with the notable exceptions of Athens and Sparta.

Spartans and Athenians refuse the Persian rule

Spartans throw Persian envoys into well, by M. A. Barth, Public domain, via Wikimedia Commons

The Persian heralds in Athens were thrown into a pit, and their Spartan brethren followed suit by tossing theirs into a well. Enraged, Darius launched his invasion of mainland Greece and met with further success until an encounter against 10,000 Athenians in Marathon.


Outnumbering the Greeks by 2.5 to 1, Darius saw an easy win- only for the Athenians to achieve a dramatic victory and force Darius to retreat. Nursing a very wounded ego, Darius planned an imminent re-invasion, with plans to raze Athens to the ground- but internal politics delayed these plans and Darius died of old age. Seeking to avenge the pride of his dead father, Xerxes prepared for a decisive campaign to end Greek independence forever.

Xerxes continues seeking the avenge of his dead father

Scene of the Battle of Marathon, by John Steeple Davis, Public domain, via Wikimedia Commons

Remembering well the lessons at Marathon, Xerxes took his time to build a sizable force. Though some historical accounts tell of a force up to 2.5 million strong- these are an almost certainly gross exaggeration, and it’s more likely that Xerxes marched with 200,000 to 250,000, though for the ancient world this would certainly have been an incredible and mind-boggling number.

Xerxes’ plan was simple: march into Greece through the north, and outflank any Greek defenders by landing his navy behind them along the Greek coast. Many Greeks feared Xerxes’ invasion force and remembered well the fate of Eretria in the first invasion which was razed to the ground and all of its people enslaved.


Spartans and Athenians fight back

Spartans marching into battle, 300 (Movie), Warner Bros. Pictures on YouTube

Thus many Greek cities bid for peace, but Athens and Sparta along with some key allies would hear nothing of it. Spartan King Leonidas marshaled a force of 300 of his personal bodyguards and helots and took command of the briefly unified Greek forces numbering at 7,000.

Despite the way, the battle was popularized by popular culture in entertainment such as the film 300, the bulk of the Spartan army did not march in support of its king because the Spartans greatly feared that the helots they held as slaves might break into all-out revolt if the army left and didn’t take them with them. 

Knowing victory would be impossible if the Persian forces simply outflanked them by sea, Athens marshaled a force of 271 triremes to sail into battle against 1,207 Persian ships.


Outnumbered both on land and at sea, the Greeks stood little chance of victory- a collapse of the Spartan position at Thermopylae would allow the fleet to be flanked, and a defeat at sea would place the ground defense in jeopardy. Outnumbered by incredible ratios, victory was unlikely- a fact Athens knew well as it had already begun the evacuation of its city.

Persian army wasn’t prepared for might of Greeks armor

Spartan phalanx (shield wall), 300 (Movie), Warner Bros. Pictures on YouTube

The Persian army at the time was equipped for battle on the plains of Asia, and as such wore mostly leather and cloth armor and shields made of wicker. They carried short spears and wielded large daggers and swords.

Most notably, the Persians- likely accustomed to fighting less well-armored opponents than the Greeks- made extensive use of archers, which was part of the reason for their defeat at Marathon: the lightly armed Persian archers could not penetrate the armor of the Athenian forces, and when closed to melee range were made short work of.

Persian Immortals, by Pergamon Museum, CC BY 2.0, via Wikimedia Commons

Leading the Persian troops was a force of 10,000 Immortals- a cadre of elite soldiers famed for always maintaining a standing force of exactly 10,000, hence the name Immortals. When any member was killed, wounded, or became sick, they were immediately replaced, thus leaving the Immortals a cohesive unit through any conflict. The Immortals were Persia’s elite heavy infantry, and often served as guards to the God-Kings themselves.

Greek fleet was made for war, Persian for supplying

Disaster to the Persian fleet off Euboea’s eastern shore, by Abbott, Jacob, 1803-1879, Public domain, via Wikimedia Commons

At sea, the Persians fielded the warship of the day: the Trireme. Powered by a combination of sails and oars, Triremes were equipped with a bronze-sheathed battering ram which it used to ram enemy vessels. However it’s unlikely that these violent crashes would actually sink an enemy ship, and most of the fighting was done in hand-to-hand combat by the marines and slaves who manned the ships.

Formidable for their time, Triremes were also notoriously poor sea-going vessels and had to stick close to shore and operate only during relatively calm seas. A series of storms prior to the battle would see nearly a third of the Persian fleet sunk, severely lowering their naval power.


To complicate matters, a great deal of the Persian fleet was also made of supply and support vessels, not dedicated warships, as opposed to the military vessels and crews of the Athenians and their allies.

Greeks equipment was far superior then Persians

Greek hoplite equipment, by Tilemahos Efthimiadis, CC BY-SA 2.0, via Wikimedia Commons

Greek ground forces were far better equipped for combat than their Persian counterparts. A greek hoplites‘ primary weapon was a two-three meter spear with a leaf-shaped blade at one end and a short spike at the other. This allowed Greek troops to fight in the famed phalanx formation, and presented any would-be attackers with a unified front of long spears to contend with.

Armed as they were with shorter spears and swords, the Persians found this difficult to overcome. Greek infantry was also equipped with large bronze-layered shields called hoplons, which offered unparallelled protection versus the wicker shields in use by the Persians.


On their bodies, Greek soldiers wore heavy bronze breastplates, bronze greaves, and helmets also made of bronze. The use of bronze and heavy armor would prove to be a decisive advantage for the Greeks. At sea the mostly-Athenian fleet was also equipped with the Trireme- however unlike the Persian forces nearly all of the Greek ships were military vessels. Having become rich from their silver mines, the Athenians had decided to invest heavily into a formidable fleet, which in turn made them undisputed masters of the Aegean.

The Battle of Thermopylae

Scene of the Battle of Thermopylae, by John Steeple Davis, Public domain, via Wikimedia Commons

As Persian forces marched south into Greece, Leonidas led his small army for the pass at Thermopylae, which at the time was no more than 50 feet across (15 meters) and bordered on one side by tall cliffs, and the ocean on the other. The pass allowed Greek forces to make the best use of their formidable phalanx formation, while completely denying the Persians the advantage of their overwhelming numbers.

Massing his forces before the Greek position, Xerxes dispatched a spy to ascertain what the Greeks were up to- only for the astonished spy to return and report that the Greeks were stripping nude for exercise and fixing each other’s hair, a common tradition, especially amongst the Spartans.


Infuriated by the rejection, Xerxes ordered his troops forward into battle

Xerxes mad at rejection, 300 (Movie), CINEVERSAL on YouTube

Sending a formal messenger, Xerxes offered the assembled Greeks a truce: the defenders should surrender and become allies to Xerxes in exchange for being allowed to retreat unharmed and being granted some of the lands of those who resisted. The offer was debated amongst the assembled Greeks, with many wanting to accept it- including a number of Spartans- but in the end, it was Leonidas’ leadership that kept the alliance together.

Funneled into the narrow pass, the Persian forces ran into the shields and spears of the Greek defenders, not making as much as a dent. Armed with short spears and swords, Persian forces could not penetrate the layers of the Greek Phalanx, and thousands died while the Greeks suffered few losses.

Enraged, Xerxes ordered his famous Immortals into the fray, confident of their victory- yet even the Immortals met with the same fate: death on the spear points and shields of the Greek phalanx.


Meanwhile, at sea, a storm had scattered and decimated the Persian fleet, allowing the smaller and much more mobile Greek fleet to target small scattered groups of Persian ships and destroy them. On the first day alone the Greeks captured 30 ships and destroyed many more, and on the second day of battle, the Greek navy completely destroyed the flotilla of the Cilicians, a vassal of the Persian Empire. Despite all odds, it seemed victory may just have been possible.

Betrayed by one of their own

The route around Spartans told by Ephialtes, by BMartens, licensed under CC BY-SA 3.0, via Wikimedia Commons

Yet at night of the second day, fate turned against the Greek defenders- or perhaps the inevitability of facing off against such overwhelming numbers. Though legend states that a Greek defector known as Ephialtes contacted Xerxes and offered to show the Persians a route around the Greek position, in all likelihood, it was simply a matter of time that Persian scouts discover the hidden path.

Knowing of the secret path, Leonidas stationed a force of 100 to defend it- but caught by surprise the defenders were quickly scattered by advancing Persian forces. Receiving news of the imminent encirclement, Leonidas considered his options and chose to order the majority of his forces into retreat, while making one last stand against the advancing Persians.


Death was certain, and history has long debated why Leonidas chose to stay and fight. Some accounts state that an oracle had declared that Sparta would only be saved by the death of one of its kings, and thus Leonidas was prompted by prophecy.

However in all likelihood, Leonidas chose to stay and fight as a matter of sheer military necessity- without a rearguard to protect the Greek retreat, retreating forces would be decimated by the advancing Persians. Prudent, but given the character of Leonidas and his agreement to ally with Athens and other former enemies, it is also likely that Leonidas’ choice was based on some level of idealism as well.

Final stand against Persians

Spartans last stand, while surrounded by Persians, Unkown (published in 1832), Public domain, via Wikimedia Commons

For centuries Greece had been divided, and in fact many historians agree that if Greece had ever unified and remained unified, it could have conquered the ancient world and then resisted the future advances of the Macedonians and Romans.


Sadly though Greece remained a fractured land of warring city-states, and only in this time of great need had the bitterest of rivals allied together for their shared defense. If Leonidas could ensure the retreat of a unified Greek force, and then make one last, valiant stand against these foreign invaders, perhaps his sacrifice could rally the rest of Greece and show them what they were capable of standing side by side as free Greeks, and not enemies.

Holding his ground with his remaining Spartans, a force of Thespians and Thebans, the Greeks reformed into a compact phalanx- with the exception of the Thebans who surrendered to Xerxes without a fight. Flanked on both sides, a final battle raged with terrible violence, and yet despite being outnumbered, superior Greek training and equipment took a heavy toll on the Persians.

Leonidas was eventually killed, though his surviving Spartans viciously fought back Persian forces four times to retrieve his body. Eventually, even these Spartans were overcome, and Leonidas’ body was crucified, his head placed on a stake to serve as a warning against further insurrection.


Greeks also took a beating on the sea

Battle of Thermopylae and Artemisium, by Eric Gaba derivative work: MinisterForBadTimes, CC BY-SA 3.0 via Wikimedia Commons

At sea, the battle also took a turn for the worst. Despite two days of stunning successes, Persian naval forces regrouped on the third day and won a decisive victory against the Greek fleet. Knowing that the battle at Thermopylae had been lost, Greek forces retreated to assist in the final evacuation of Athens.

The Battle of Thermopylae would come to be known as a pyrrhic victory- or a victory where the cost is so high, that it can hardly be considered a victory at all. Xerxes had his revenge against Athens, yet as his troops arrived the city had already been evacuated of all but the most stubborn of elders. Razing the city to the ground, Athens was nevertheless preserved in spirit as its population had already fled.

The deciding battle – Battle of Salamis

Battle of Salamis illustration, by Wilhelm von Kaulbach, Public Domain, via Wikimedia Commons

Though the ground battle at Thermopylae is the engagement that history remembers best, it was actually the battle waged by the mostly Athenian fleets at Battle of Artemisium, that would inevitably lead to the defeat of Persian forces. A minor military victory at the time, the battles at Artemisium nevertheless gave Greek forces insight into how the Persian fleet operated and allowed them to devise plans to defeat them in future battles.


It also weakened the Persian fleet, losses combined with those suffered at sea during freak storms that preceded the battle, were hard to replace. Despite their recent defeat, the Athenian general Themistocles persuaded the Greek allies into one decisive engagement against the Persians, knowing that if they could be defeated at sea Xerxes’ ground forces would be forced to retreat as well. Lured into the narrow Straits of Salamis by a cunning ploy on Themistocles’ behalf, the Persian fleet- bottled up and unable to maneuver- was handily defeated.

With supply lines cut off and his navy decimated, Xerxes retreated to Asia with most of his army but left a sizable portion to continue the conquest of Greece. One year later though a unified Greek force engaged the Persian army at the Battle of Plataea and secured a decisive victory, effectively ending the Persian threat to the Greek mainland.

The importance of Thermopylae was manifold for the Greek people, yet of greatest import may perhaps have been the evacuation of the Athenian people- bought and paid for by the blood of the brave men who defended that narrow pass for three days. This preserved Athenian culture, and with so many of our modern values tracing their roots to ancient Greece, who can know what our world might look like today had Athens been eradicated as planned.


Though perhaps, we would have barely noticed the difference. Demonized as they have been in popular media by films such as 300, the Persians actually made many contributions to the development of democracy and were a fairly progressive people. In the end, the failed conquest of Greece and the great sacrifices at the battle of Thermopylae may all have been nothing more significant than the failed ambitions of the human ego.

Featured image: Art representation of Battle of Thermopylae, by Cleber.knfire, CC BY-SA 4.0, via Wikimedia Commons