In 480 BC, an enormous Persian army under the chief command of Emperor Xerxes (son of Darius the Great) campaigned against Thessaly in central Greece. Mainly they fought against the southern mostly democratic and independent city/states. The army numbered more than 300,000 men.
The Hellenes initially decided to defend themselves in Tempe valley (next to Mount Olympus) by sending about 10,000 fighters. Yet, a couple of months later they concluded that it was better to stand at the Thermopylae straits (about 150 km (93 miles) to the north of Athens), where, however, only a total of 7,000 hoplites could gather.
Artistic representation of the Battle of Thermopylae. (Internet Archive Book Images/ Commons)
War During the Olympics
Like in Marathon 10 years earlier when the Spartans had their religious festival of Karnea dedicated to Apollo, at the end of summer in 480 BC people from all over the Hellenic lands (including those in Africa and Sicily) participated to the Olympic Games. The Games were dedicated to Zeus and war was forbidden when they were held.
The Persians knew about these ceremonies and had chosen (once again) to campaign against Greece during the summer. Much to their surprise, they faced approximately 6,000 hoplites from various Hellenic regions at Thermopylae (4,000 from the Peloponnese and 2,000 from around Thermopylae). Due to the urgent situation, the five Ephores (curators) of Laconia allowed the Spartan king Leonidas, along with 300 hoplites and about 1000 helots, to fight during the Olympic Games.
Leonidas I of Sparta. ( Praxinoa/CC BY SA 3.0 )
It must be noted that during ancient times the Thermopylae straits were as narrow as 10 to 100 meters (32.8 -328 ft.), bordered on one side by abrupt mountain cliffs (towards the south) and on the other side (the north) by the sea. This was the main passage to reach southern Greece, although the terrain in this area is varied (full of anomalous mountains) all the way to the Ionian Sea.
View of the Thermopylae pass at the area of the Phoenician Wall. In ancient times the coastline would have been where the modern road lies, or possibly even closer to the mountain. (Fkerasar/ CC BY SA 3.0 )
The Battle Begins
For the first four days, Xerxes waited for the Hellenes to abandon the straits. He asked Leonidas to give up his weapons – to which he received the proud and Laconic answer “Come and get them” (μολών λαβέ). Thereafter, for the next three days, the Persian army encountered strong resistance (losing at least 20,000 men). For a total of one week it was impossible for Xerxes to pass through Thermopylae.
Eventually, the imperial army saw it necessary to retreat to Asia. This was probably due in part to providing such a large army with supplies. In truth, it is also important to note that the Hellenes, contrary to their opponents, were more trained in phalanx fights and possessed better weapons (longer pikes, larger shields, metallic panoplies etc).
Top: A Greek phalanx formation. ( Public Domain ) Bottom: Four Persian warriors of ‘The Immortals’, from the glazed brick friezes found in the Apadana (Darius the Great’s palace) in Susa. ( Immortels/CC BY SA 2.0 )
However, the biggest problem faced by the small Hellenic army was that of encirclement (the same as in Marathon). Trying to achieve such a goal, Xerxes initially sent more than half of the 1,300 Persian (principally Phoenician) warships towards the Euboea gulf at the same time as the Thermopylae battle.
He hoped to disembark troops at the rear of the straits’ defenders. Xerxes’ maneuver was prevented by Themistocles (a hero, general, and fighter during the Marathon battle against the “auriferous” Medes in 490 BC). Themistocles oversaw 280 Athenian warships and defeated the imperial fleet three times within two days during naval battles near Artemission (about 40 nautical miles from Thermopylae).
Some sudden storms in the region also destroyed many Persian ships. Thus, legends say the Hellenes’ effort was “helped” by the gods as well. It is more than obvious that the Athenians (and also Thespians and eventually Plataeans) were very anxious about the outcomes of the battles at Thermopylae and Artemisson.
Campaign map for the Battles of Thermopylae & Artemisium (Artemisson) (480 BC), based on the description of Herodotus. ( CC BY SA 3.0 )