The glorious mythology of Thermopylae is, of course, justified by the heroism of the ferocious three days resistance and the ultimate, willing sacrifice of the rearguard.The leadership and commitment demonstrated by Sparta, Greece\'s foremost warrior nation, and the extraordinary example of Leonidas and his 300, and of the 700 Thespians, perhaps the entire hoplite strength of that small city, who died alongside them, undoubtedly strengthened the morale and resolution of the Greek alliance (though the outcome also persuaded some wavering cities not to join it). The hard lesson the Persians had learned at Marathon was reinforced under the critical gaze of the Great King. But the mythology of the land battle rapidly inflated its historical and strategic importance above that of the simultaneous sea battle at Artemisium and reduced the parallel naval action to the status of a lesser sideshow.
Thermopylae was a hoplite battle and the Greeks were led by a Spartan king. Excelling with spear and shield in the phalanx was far superior to pulling an oar in a trireme, work for lowlier citizens, resident aliens and slaves.As representatives of the leading citizen class in the developing democracies, exercising free will in obedience to their laws, the hoplites contrasted sharply with the Great King\'s "slave" troops. And although the Greek fleet was also led by a Spartan, an aristocrat though not a king, Themistocles, the Athenian man of the people, was truly in command, and 200 of the 324 triremes finally deployed were supplied and mostly manned by Athens.
When the first historical accounts were being written, the Athenians had become losers in the Peloponnesian War, and were also seen as its instigators. They were not popular in Greece. However, in terms of assets, the Greek commitment was far greater at Artemisium than at Thermopylae. The triremes themselves represented massive capital investment and were irreplaceable within the probable timescale of the war, even supposing timber was immediately available. 70,000 is a reasonable estimate of the total manpower deployed with perhaps 5,000 drawn from the hoplite elite to serve as marines. Less than 6,000 hoplites were committed on the first day at Thermopylae, supported by about the same number of light-armed and support troops, 12,000 in all.
Defeat at Thermopylae was as tragic as it was inevitable, and it was necessary to make a stand there if the Greeks were also to fight at Artemisium, but it was survivable as long as the navy held. Defeat at Artemisium, yielding control of the sea to the Persians, would have lost the war. Artemisium would then indeed have been one of those “battles that changed history”.
Not surprisingly in view of the mythology, Herodotus says rather less about Artemisium than about Thermopylae, and later sources add very little.But at least Plutarch, writing half a millennium later, somewhat redresses the balance in his largely unflattering Life of Themistocles. He points out correctly that Artemisium was inconclusive (a bruising score draw would be a fair description!) but quotes with approval this fragment written by the 5th century BC poet Pindar: “Here the sons of Athens put in place the bright foundation stone of freedom”.