How many Persians fought against the 300 Spartans at Thermopylae?

Answer 1

Who was there

The 300 Spartans were Spartan king Leonidas' bodyguard. Sparta was concerned with defending its own land from a Persian amphibious raid, and so was not about to send off a main force. Leonidas also had about 2,000 serf-light infantry. There were also about 4,000 warriors from those Greek states in the Thermopylai area which had not already gone over to the Persians.

How do we tell who won?

Who won hangs on the objectives of the both sides, and who was successful in achieving them.

What were the objectives and outcomes?

The Persian objective was to capture peninsular Greece to establish an ethnic frontier, as the latter had been supporting revolution in the Greek cities along the coast of Asia Minor, which was part of the Persian Empire. Xerxes had a large land force of about 150,000 infantry and 30,000 cavalry, and 600 warships with 120,000 crewmen.

The Persian war fleet was superior to the Greek one, so it provided both outflanking amphibious capability and protection for the resupply fleet; the amphibious capability meant the Greek forces could not concentrate, remaining at home defending their cities, and so able to be picked off one by one.

The Greek strategy was to neutralise this war fleet, both to even up the operational mobility equation and, by depriving the Persians of their essential sea supply route, ultimately force their withdrawal. Given the inequality of the fleets, the Greeks determined to force sea engagements in narrow waters to minimise the effect of the opposing superior ships and numbers: they closed the land route to the south at the Thermopylai pass to force a Persian outflanking amphibious operation in the adjacent strait. When three days of naval engagements failed to give a Greek victory, and the Thermopylai position was outflanked on land, the fleet withdrew to the strait between Salamis and Athens, and by a stratagem of splitting the Persian fleet, defeated the main force and so exposed the sea supply line.

With no resupply, Xerxes was obliged to take half his army back to Asia Minor and the remaining part had to withdraw and winter in northern Greece. The following spring the southern Greek states, no longer threatened by enemy amphibious landings, were able to concentrate in full strength at Plataia and defeat the remaining Persian army and its Greek allies. In parallel, the Greek naval forces captured the rump of the Persian fleet at Mykale in Asia Minor.

Romantic stories of the stand at Thermopylai, based on it being designed to defeat the invasion, conceal the real strategies of both adversaries. The centre of gravity of the might of Persia outside Asia was its Egyptian, Phoenician and Asian-Greek war fleet. Its neutralisation mandated a critical enemy land force reduction and removed the threat of amphibious invasion of the Peloponnese states, allowing them to concentrate against the reduced enemy land forces.

So who won at Thermopylai?

The Persians continued with their invasion until stopped elsewhere.

The Greeks lost the naval engagement offshore, which was set up by the Thermopylai defence, so the latter was to no avail. When Leonidas got news of the Persian outflanking of his position through the mountains, he sent the other contingents off to get inside the walls of friendly cities so that they wouldn't be ridden down in open country by the Persian cavalry when they broke through. He kept the Theban contingent as they were suspected of having already gone over to the Persians, and set up a last stand with his 300 Spartan hoplites and 2,000 serf-light infantry to give the dismissed contingents a head start. The Thebans quickly surrendered and the Spartan 2,300 went down to a man. The other contingents took the benefit of this sacrifice and got away safely.

Answer 2

There were 7,000 from the Greek city-states, including the 300 of Spartan King's bodyguard and their accompanying 2,000 light infantry, who opposed the Persian army of about 180,000.

The battle was a holding operation in the pass to force a sea battle in the straight nearby in an attempt to defeat the Persian navy. The sea battle failed and the task of the pass-holders ended - they went back to their cities and the Spartan 2,300 stayed and died still holding the pass to let them get away safely.

Answer 3

Lacedaemonians,acadians,Mycenaeans,Phlians and a couple of other greek forces; about 7,000 all told.