Educational Travel Lesson Plans

Classical Greece (4th-5th Centuries BCE): Battle of Thermopylae: Leonidas and the 300



Through the investigation of selected primary and secondary sources, students in this lesson will identify, understand and be able to explain how a vastly outnumbered and outgunned Greek force was able to hold out against a much larger and more powerful Persian army at the Battle of Thermopylae and why this battle is considered to be a watershed event in the history of western civilization.


World History

Grade Level



90 minutes

Tour Links

  • Thermopylae Battlefield
  • Monument to the 300, Thermopylae
  • Ancient Sparta

Essential Questions

  • What was the Battle of Thermopylae in 480 BCE?  Why did the Greek forces choose to fight the Persians there instead of another place?  Why was it an important event in the Greco-Persian Wars?
  • Who was Herodotus?  How did he describe the Battle of Thermopylae?
  • Who was Leonidas of Sparta?  Who were the “300” at Thermopylae?

Key Terms

  • Ancient Greece
  • Battle of Thermopylae
  • Leonidas
  • Persian Empire
  • Xerxes

Come back with this shield…or on it.

Saying attributed to Spartan mother as she sent her son to battle, from Plutarch, Sayings of Spartans, 1st century CE

Gorgo to Leonidas: “What should I do?”

Leonidas to Gorgo: “Marry a good man and have good children.”

Conversation attributed to Leonidas and his wife on his leaving for Thermopylae from Plutarch, Sayings of Spartans, 1st century CE 

Go tell the Spartans, stranger passing by, that here, obedient to Spartan Law, we lie.

Epigram engraved on a commemorative stone at Thermopylae, attributed to Simonides of Ceos (Greek poet), approx. 470 BCE

“Mardonius, what kind of men are these that you have pitted against us?  It is not for riches they contend, but for honor.”

Saying attributed to King Xerxes when referring to the Greeks after the Battle of Thermopylae

He had now come to Thermopylae, accompanied by the three hundred men which the law assigned him, whom he had himself chosen from among the citizens, and who were all of them fathers with sons living. On his way he had taken the troops from Thebes, whose number I have already mentioned, and who were under the command of Leontiades the son of Eurymachus. The reason why he made a point of taking troops from Thebes, and Thebes only, was that the Thebans were strongly suspected of being well inclined to the Medes. Leonidas therefore called on them to come with him to the war, wishing to see whether they would comply with his demand, or openly refuse, and disclaim the Greek alliance. They, however, though their wishes leant the other way, nevertheless sent the men. 

The Greek forces at Thermopylae, when the Persian army drew near to the entrance of the pass, were seized with fear; and a council was held to consider about a retreat. It was the wish of the Peloponnesians generally that the army should fall back upon the Peloponnese, and there guard the Isthmus. But Leonidas, who saw with what indignation the Phocians and Locrians heard of this plan, gave his voice for remaining where they were, while they sent envoys to the several cities to ask for help, since they were too few to make a stand against an army like that of the Medes.

… But Xerxes was not persuaded any the more. Four whole days he suffered to go by, expecting that the Greeks would run away. When, however, he found on the fifth that they were not gone, thinking that their firm stand was mere impudence and recklessness, he grew wroth, and sent against them the Medes and Cissians, with orders to take them alive and bring them into his presence. Then the Medes rushed forward and charged the Greeks, but fell in vast numbers: others however took the places of the slain, and would not be beaten off, though they suffered terrible losses. In this way it became clear to all, and especially to the king, that though he had plenty of combatants, he had but very few warriors. The struggle, however, continued during the whole day.


Then the Medes, having met so rough a reception, withdrew from the fight; and their place was taken by the band of Persians under Hydarnes, whom the king called his "Immortals": they, it was thought, would soon finish the business. But when they joined battle with the Greeks, 'twas with no better success than the Median detachment- things went much as before- the two armies fighting in a narrow space, and the barbarians using shorter spears than the Greeks, and having no advantage from their numbers. The Lacedaemonians fought in a way worthy of note, and showed themselves far more skilful in fight than their adversaries, often turning their backs, and making as though they were all flying away, on which the barbarians would rush after them with much noise and shouting, when the Spartans at their approach would wheel round and face their pursuers, in this way destroying vast numbers of the enemy. Some Spartans likewise fell in these encounters, but only a very few. At last the Persians, finding that all their efforts to gain the pass availed nothing, and that, whether they attacked by divisions or in any other way, it was to no purpose, withdrew to their own quarters.

During these assaults, it is said that Xerxes, who was watching the battle, thrice leaped from the throne on which he sate, in terror for his army.

Next day the combat was renewed, but with no better success on the part of the barbarians. The Greeks were so few that the barbarians hoped to find them disabled, by reason of their wounds, from offering any further resistance; and so they once more attacked them. But the Greeks were drawn up in detachments according to their cities, and bore the brunt of the battle in turns- all except the Phocians, who had been stationed on the mountain to guard the pathway. So, when the Persians found no difference between that day and the preceding, they again retired to their quarters.

Now, as the king was in great strait, and knew not how he should deal with the emergency, Ephialtes, the son of Eurydemus, a man of Malis, came to him and was admitted to a conference. Stirred by the hope of receiving a rich reward at the king's hands, he had come to tell him of the pathway which led across the mountain to Thermopylae; by which disclosure he brought destruction on the band of Greeks who had there withstood the barbarians. . .

The Greeks at Thermopylae received the first warning of the destruction which the dawn would bring on them from the seer Megistias, who read their fate in the victims as he was sacrificing. After this deserters came in, and brought the news that the Persians were marching round by the hills: it was still night when these men arrived. Last of all, the scouts came running down from the heights, and brought in the same accounts, when the day was just beginning to break. Then the Greeks held a council to consider what they should do, and here opinions were divided: some were strong against quitting their post, while others contended to the contrary. So when the council had broken up, part of the troops departed and went their ways homeward to their several states; part however resolved to remain, and to stand by Leonidas to the last.

It is said that Leonidas himself sent away the troops who departed, because he tendered their safety, but thought it unseemly that either he or his Spartans should quit the post which they had been especially sent to guard. For my own part, I incline to think that Leonidas gave the order, because he perceived the allies to be out of heart and unwilling to encounter the danger to which his own mind was made up. He therefore commanded them to retreat, but said that he himself could not draw back with honor; knowing that, if he stayed, glory awaited him, and that Sparta in that case would not lose her prosperity. For when the Spartans, at the very beginning of the war, sent to consult the oracle concerning it, the answer which they received from the Pythoness was "that either Sparta must be overthrown by the barbarians, or one of her kings must perish." 

So the allies, when Leonidas ordered them to retire, obeyed him and forthwith departed. Only the Thespians and the Thebans remained with the Spartans; and of these the Thebans were kept back by Leonidas as hostages, very much against their will. The Thespians, on the contrary, stayed entirely of their own accord, refusing to retreat, and declaring that they would not forsake Leonidas and his followers. So they abode with the Spartans, and died with them. Their leader was Demophilus, the son of Diadromes.

At sunrise Xerxes made libations, after which he waited until the time when the forum is wont to fill, and then began his advance. Ephialtes had instructed him thus, as the descent of the mountain is much quicker, and the distance much shorter, than the way round the hills, and the ascent. So the barbarians under Xerxes began to draw nigh; and the Greeks under Leonidas, as they now went forth determined to die, advanced much further than on previous days, until they reached the more open portion of the pass. Hitherto they had held their station within the wall, and from this had gone forth to fight at the point where the pass was the narrowest. Now they joined battle beyond the defile, and carried slaughter among the barbarians, who fell in heaps. Behind them the captains of the squadrons, armed with whips, urged their men forward with continual blows. Many were thrust into the sea, and there perished; a still greater number were trampled to death by their own soldiers; no one heeded the dying. For the Greeks, reckless of their own safety and desperate, since they knew that, as the mountain had been crossed, their destruction was nigh at hand, exerted themselves with the most furious valor against the barbarians.

By this time the spears of the greater number were all shivered, and with their swords they hewed down the ranks of the Persians; and here, as they strove, Leonidas fell fighting bravely, together with many other famous Spartans, whose names I have taken care to learn on account of their great worthiness, as indeed I have those of all the three hundred...

Thus two brothers of Xerxes here fought and fell. And now there arose a fierce struggle between the Persians and the Lacedaemonians (Spartans) over the body of Leonidas, in which the Greeks four times drove back the enemy, and at last by their great bravery succeeded in bearing off the body. This combat was scarcely ended when the Persians with Ephialtes approached; and the Greeks, informed that they drew nigh, made a change in the manner of their fighting. Drawing back into the narrowest part of the pass, and retreating even behind the cross wall, they posted themselves upon a hillock, where they stood all drawn up together in one close body, except only the Thebans. The hillock whereof I speak is at the entrance of the straits, where the stone lion stands which was set up in honor of Leonidas. Here they defended themselves to the last, such as still had swords using them, and the others resisting with their hands and teeth; till the barbarians, who in part had pulled down the wall and attacked them in front, in part had gone round and now encircled them upon every side, overwhelmed and buried the remnant which was left beneath showers of missile weapons. 

Thus nobly did the whole body of Lacedaemonians (Spartans) and Thespians behave; but nevertheless one man is said to have distinguished himself above all the rest, to wit, Dieneces the Spartan. A speech which he made before the Greeks engaged the Medes, remains on record. One of the Trachinians told him, "Such was the number of the barbarians, that when they shot forth their arrows the sun would be darkened by their multitude." Dieneces, not at all frightened at these words, but making light of the Median numbers, answered "Our Trachinian friend brings us excellent tidings. If the Medes darken the sun, we shall have our fight in the shade." Other sayings too of a like nature are reported to have been left on record by this same person.

Herodotus, The Histories, 5th century BCE

August 480 BCE…Thermopylae Pass, Greece

Xerxes, the Persian god-king, commanded a force larger than any the world had ever seen, one the ancient historian Herodotus estimated at over 1 million (probably exaggerated -- modern historians say it was probably between 150,000 and 200,000).  Persian soldiers came from across an empire that stretched from India to the steps of southeastern Europe.  Persian heavy infantry soldiers, known as the “immortals”, were feared across the region for their fighting prowess and invincibility, a fighting force unmatched in the ancient world.  After their stunning and unexpected defeat at the hands of the Greeks 10 years earlier at the Battle of Marathon, the Persians were determined to crush any opposition.  This time, overwhelming superior forces would carry the invasion.  Greece would fall and Xerxes would make an example of the Peloponnesians so that no one would again challenge mighty Persia.  The god-king, thinking his army would simply be able to overwhelm any opposition, chose an overland route into Greece.  At the same time his navy would cut off the Greeks from the sea.  This strategy would bring the Persian army though the mountains of northern Greece, enabling them to trap the Greeks on their own peninsula.  

Opposing the great army was a hastily assembled and vastly outnumbered force of around 6000 Greek citizens, mostly merchants and farmers, from different city states across the peninsula.  They were brave souls willing to fight against tyranny, but most were not soldiers.  There was, however, one small exception.  Leading the Greek armies was a small contingent of 300 warriors from Sparta, led by their king, Leonidas.

Leonidas knew full well the position his army was in.  His task was to hold up the Persians long enough for the rest of Greece to rally together.  Leonidas had chosen the ground wisely.  The pass at Thermopylae was narrow, perhaps 200 yards across at one point.  The Greeks would hold the pass as long as they could, bottling up the Persian army and effectively negating its numbers.  The king also knew his task was, in the end, hopeless.  There were simply too many opposing him.  He also knew he and his 300 could never retreat nor withdraw.  There could be no surrender.  Spartan ethos demanded nothing less than victory or honorable death.  Leonidas knew victory would not come. 

The Greek alliance at Thermopylae held for three days as wave after wave of attack came.  Thousands of Persian dead littered the field, but Xerxes kept pushing.  Leonidas and his warriors may have held up Xerxes indefinitely, but Herodotus says that the Greeks were betrayed by one of their own citizens, one who gave the Persians information about a back route around the “Hot Gates”.  When the Greek commanders realized the situation was hopeless, most of them took their forces home, leaving the remaining Spartans and a small contingent of other Greeks (mostly Thespians) to give the ultimate sacrifice.  Herodotus states that the Spartans and Thespians died honorably to the last man, finally falling to the overwhelming force as Persian archers rained death from the sky.   The Battle of Thermopylae was over. 

The victory cost Xerxes dearly.  Casualty numbers have been debated for centuries.  Herodotus says that over 20,000 Persians died, long with over 4000 Greeks.  Both numbers are probably too high, but it’s safe to say that the Persian army’s aura of invincibility was badly shaken.  Nonetheless, Xerxes marched his army into the Peloponnesus and towards Athens, but the story of Leonidas and the sacrifice of the Greeks at Thermopylae spread across Greece quickly. 
Within a year, the Greeks had defeated what was left of the Persian army and Xerxes was home in ridicule.  He would never again try to invade the little peninsula.  

The Battle of Thermopylae is arguably the most famous battle before 1000 CE, certainly ranking up there with Zama during the Punic Wars (2nd century BCE) and Tours in 732 CE.  For centuries, students, scholars, historians and military strategists have studied it, and they continue to do so.  It’s heavily covered in courses at West Point.  Leonidas has gone down among the most famous kings and generals in history. But it’s not just for the pyrrhic quality that the battle is examined, although the damage to Xerxes and his army cannot be understated.  Perhaps people are drawn to the sacrifice of those gallant warriors because they see an extreme example of individual sacrifices for the benefit of others.  Perhaps it’s the same reason we study those killed at the Alamo, or those who ran back into the towers on 9/11, or why we remember any soldier who gives (as Abraham Lincoln in 1863 called it) the “last full measure of devotion” in battle.  

Through the investigation of selected primary and secondary sources, students in this lesson will identify, understand and be able to explain how a vastly outnumbered and outgunned Greek force was able to hold out against a much larger and more powerful Persian army at the Battle of Thermopylae and why this battle is considered to be a watershed event in the history of western civilization.

educational tour image
  1. Students will identify, understand and be able to explain how a vastly unnumbered and outgunned Greek force was able to hold out against a much larger and more powerful Persian army at the Battle of Thermopylae.
  2. Students will identify, understand and be able to explain why the Battle of Thermopylae in 480 BCE is considered to be a watershed event in the history of western civilization.

To view resource web pages, download the lesson plan PDF above.

I. Anticipatory Set

  • Writing / Question: How important is defending one’s homeland in preparation for battle? (5 min)
  • Handouts – Copies of documents and readings from the websites listed. (5 min)

II. Body of Lesson

  • Lecture / PPT – Battle of Thermopylae (25 min)
  • Video – Battle of Thermopylae (15 min)
  • Independent Activity – Students read the articles and sources on the Battle of Thermopylae, taking notes as appropriate. (20 min)
  • Suggestion: Have the students read some of these articles and sources for homework before class.
  • Suggestion: Advanced / AP students should focus on primary sources
  • Group Activity – Socratic Seminar: Discussion on the Battle of Thermopylae (15 min)

III. Closure

  • Assessment / DBQ – Essay: Explain in detail how a vastly outnumbered and outgunned Greek force was able to hold out against a much larger and more powerful Persian army at the Battle of Thermopylae and why this battle is considered to be a watershed event in the history of western civilization.


On tour: Thermopylae Pass, Greece

While on tour in Greece, students can visit the Thermopylae Pass, where they can see for themselves where Leonidas and the 300 made their final stand against the Persians (with help from their friends – many of whom are forgotten to history). On the site are two monuments, one to the Spartans and one to the Thespians. Archeological digs at the site are ongoing. Thousands of artifacts from the battle have been recovered and are now in museums. Leonidas was obviously killed at the site, but his body is now in Sparta. Perhaps students can reflect on what it means to “come back with this shield…or on it”?


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