On 18-20 August 480 BCE, the Battle of Thermopylae was fought between the Greeks under Leonidas I and the Persians under Xerxes I during the Greco-Persian Wars.
Why did it happen?
In 486 BCE, Xerxes succeeded his father Darius I as King of Persia. He then set in motion meticulous plans for the conquest of Greece. By 480 BCE, he had assembled a massive army and navy of 200,000 troops and 1,200 warships and crossed the Hellespont into northern Greece. While most Greek cities surrendered, Athens and Sparta chose to resist. Under Themistocles, the Greeks sent a navy northward to engage the Persian fleet at Artemisium. At the same time, King Leonidas of Sparta led an army of Greek hoplites and skirmishers north to Thermopylae where he planned to hold off the Persians for as long as possible. While the Persian navy was battered by storms on its way down the coast of Greece, the Persian army under Xerxes arrived at Thermopylae on 14 August to meet the much smaller Greek army which had positioned itself in front of the only route south into Greece.
Who was involved?
The Greek army at Thermopylae numbered 7,000 hoplites and skirmishers and included 300 Spartans, 700 Thespians and 400 Thebans. The Greeks fought in a phalanx, which was essentially a compact formation of spears and shields. The phalanx was almost impenetrable from the front but extremely vulnerable on the flanks and rear. To avoid being outflanked, the Greek phalanx positioned itself between the mountains on their left flank and the sea and Phocian Wall on their right flank. The Persian army at Thermopylae numbered 200,000 men, making it one of the largest armies ever assembled in ancient history. Despite their superior numbers, however, the narrow pass of Thermopylae served to funnel the Persians into the confined space, negating their advantage in numbers and turning it into a battle of attrition. The Persians, who wore only light clothing and wielded shorter spears were at a disadvantage to the longer spears and round shields of the Greek army.
What happened?
At dawn on 18 August, after a barrage of arrows from the Persian archers failed to disorder the Greek hoplites, Xerxes ordered a frontal assault on the Greek phalanx, only for his Persian infantry to suffer heavy casualties. Towards the end of the day, Xerxes ordered his 10,000 strong bodyguards, the Immortals, to attack the Greek hoplites. Leonidas defeated the Immortals by successively placing different Greek contingents in the frontline and staging several feigned retreats which drew the Persians forward into attacking the Greeks. On 19 August, believing that the Greeks had been worn out after the previous day’s battle, Xerxes ordered his Medes and Cissians to launch another frontal assault on the Greek hoplites. Once again, the Persians were repulsed with heavy casualties. At the end of the day, a Greek traitor named Ephialtes led the Persians along a hidden goat path through the mountains around the Greek position. The 1,000 Phocians Leonidas had sent to guard the mountain path were scattered without a fight. At dawn on 20 August, Leonidas ordered most of the Greek army to withdraw while he made a final stand with his 1,400 Spartans, Thespians and Thebans. After heavy fighting, Leonidas was killed by an arrow while the 300 Spartans and 700 Thespians were killed to the last man. Only the Thebans surrendered. Throughout the three days of the battle, the Persians lost 20,000 men while the Greeks lost only 1,000 men, most of those casualties being on the last day of the battle.
What changed as a result?
The Battle of Thermopylae was a Persian victory. However, it was a case of winning the battle but losing the war. In 479 BCE, the Persian army was crushed by a force of 5,000 Spartans and 18,000 other Greeks at the Battle of Plataea, thereby bringing the Second Persian Invasion of Greece to an end. In the centuries after the Greco-Persian Wars, Thermopylae would be remembered in the Western world for its acts of heroism and self-sacrifice by Leonidas and his 300 Spartans. As Jennifer Roberts states, “What transpired at Thermopylae has been burned in the memory of Western Civilisation” (Schmidt, 2002). A plaque erected at Thermopylae bears this out. It reads, “Go tell the Spartans, stranger passing by, that here obedient to their laws we lie” (Schmidt, 2002).
Bibliography
Grant, R.G. Battle: A Visual Journey Through 5,000 Years of Combat. London, Dorling Kindersley, 2005.
Harwood, Jeremy. Atlas of History’s Greatest Military Victories. London, Quantum Publishing, 2013.
Schmidt, Richard. The Rise and Fall of the Spartans. USA, History Channel, 2002. DVD.
Snow, Peter. Battles Map by Map. London, Dorling Kindersley, 2021.