Evidently, the Athenian demos was growing more bold, as the Constitution of Athens puts it. This was equally true in foreign affairs. The year after Marathon, Miltiades made an attack on the Aegean island of Paros, which anticipates the more systematic imperialism of the period after 479. And it is possible that the Athenian duel with Aegina continued into the 480s. But the event with the greatest implications for foreign policy was a sudden large increase in the output of the Laurium silver mines (actually in a region called Maronea).
The evidence gives the crucial year as 483, but it is not known whether there was really a dramatic lucky strike just before that or whether this was merely the year when Athens decided how to spend the accumulated yield of several good years. One source does speak of “discovery” of mines, but the mining area had been worked since Mycenaean times, and the mines were certainly operational under the Peisistratids. It was decided to spend the windfall on building more triremes, bringing the total to 200 by 480, from the 70 attested for Miltiades’ Parian expedition of 489. The precise method somehow involved the advancing of money to individuals, an interesting partial anticipation of the Classical system of “trierarchies.”
Trierarchs, who are not specifically attested before the middle of the century, were wealthy individuals who, as a kind of prestige-conferring tax payment, paid for the equipping of a trireme (the state provided the hull). The source of the timber for this huge program is not known; perhaps local Attic or Euboean supplies supplemented Italian timber. Themistocles, who is credited with the essential decision to spend the money on ships rather than on a distribution among the citizens, had western interests that make the Italian hypothesis plausible. If this is right, the feat of transportation should be admired almost as much as the crash building program itself. One consequence of the rapidity of the program was that much of the timber must have been unseasoned; this is relevant to the eventual Greek decision at the Battle of Salamis (480) to fight in narrow waters, where the resulting loss of speed (green timber makes ships heavier and slower) would matter less. Greek alliances
It was in Athens, then, that the most energetic action was taken. Xerxes had not lost sight of the old revenge motive, a motive that ought to have meant that Athens was the main or only target, but his aim this time was—as Herodotus correctly says—to turn Greece as a whole into another Persian province or satrapy. This called for a concerted Greek plan, and in 481 the key decisions were taken by a general Greek league formed against Persia. Quarrels like that between Athens and Aegina had to be set aside and help sought from distant or colonial Greeks such as the Cretans, Syracusans, and Corcyrans, whose extraordinarily large fleet of 60 ships (possibly developed against Adriatic piracy but also—surely—against Corinth) would be a prime asset. Corcyra, however, waited on events, and Crete stayed out altogether, while Syracuse and Sicily generally had barbarian enemies of their own to cope with, the Carthaginians. (Syracuse and other parts of Sicily were now under the tyranny of Gelon.)
Greek writers found the parallel between the simultaneous threats to eastern and western Hellenism irresistible and represented Carthage as another Persia. It has, however, been suggested that the imperialistic ambitions of Carthage have been generally exaggerated by Greek writers eager to flatter their patrons, such as Gelon. The reality of the Battle of Himera, however, in which Gelon decisively defeated the Carthaginians, is not in doubt; like the Battle of Salamis, it was fought in 480, allegedly on the same day. Gelon did indeed have his own preoccupations. The Greeks may not have been altogether sorry: the tyrant Gelon would have been an ideologically awkward ally in a struggle for Greek freedom from arbitrary one-man rule.
Even without western Greek help, the Greek fleet numbered about 350 vessels, amounting perhaps to a third of the Persian fleet. The size of the Persian land army is reckoned in millions by Herodotus, and all modern scholars can do is replace his guess by far lower ones.Greek unity, though impressive, was not complete; conspicuous among the “Medizers” was Thebes, while Argos’ neutrality amounted, in Herodotus’ view, to Medism.
An inscription found in 1959, the so-called “Decree of Themistocles,” purports to contain further detailed decisions made about this time regarding the evacuation of Attica and the mobilization of the fleet. But the writing is of the 4th century, and the whole text is probably not a re-inscribing of a genuine document but a patriotic concoction of the age in which it was written and erected. Thermopylae
An initial plan to defend Thessaly was soon abandoned as unrealistic. Instead the Greeks fell back on a zone at the northeastern end of Euboea, where they hoped to defend Thermopylae by land and Artemisium by sea. Herodotus, who is often accused of failing to realize the interconnectedness of these two holding operations, did in fact stress that the two were close enough for each set of defenders to know what was happening to the other.
The Spartans had sent their king Leonidas to Thermopylae with a force of 4,000 Peloponnesians, including 300 full Spartan citizens and perhaps a helot contingent as well. They were joined by some central Greeks, including Boeotians from Thespiae and Thebes. The pass at Thermopylae could not be held indefinitely, as Leonidas surely knew, but he also knew that an oracle had said that Sparta would be devastated unless one of its kings was killed. Leonidas’ exact “strategy” has been debated as if it were a puzzle, but perhaps one should not go beyond the oracle. The king must die.
Leonidas died, with his 300 Spartans (and the helots, Thespians, and Thebans, as should be remembered to the honour of all three). The other groups, Peloponnesians and central Greeks, were all dismissed. The naval action at Artemisium was inconclusive, the real damage to the Persian ships being done by a storm as they rounded Euboea.
Whether or not the Decree of Themistocles is genuine, it is a fact that Attica was evacuated and the Athenian Acropolis sacked by the Persians. This sacrifice of their city, like the victory of Marathon, is one of the cardinal elements in Athenian celebration of the Persian Wars. The Persians destroyed the temples on the Acropolis and carried off the statues of Harmodius and Aristogiton, the two men who had assassinated the tyrant Hippias’ brother Hipparchus in 514. The symbolic importance to Athens of what happened on the Acropolis in 480 is illustrated by the subsequent history of those statues: they were returned to Athens by Alexander the Great a century and a half later as part of his claim to be punishing the Persians for their 5th-century impiety. Salamis
The Persians entered the narrows of Salamis, where Themistocles had insisted the Greeks should be stationed, and they were comprehensively defeated under the appalled eyes of Xerxes himself. This defeat is a “David and Goliath” encounter only in the general sense that the Persian empire was vastly greater, in size and resources, than the realm of its Greek opponents. It is said that the Greek ships were actually heavier and less easy to maneuver than those of their opponents. Yet this Persian advantage, and that conferred by the greater experience of the Phoenician sailors on the Persian side, were canceled out by the Greek advantages of position: a fight in the narrows would enable them to board and fight hand to hand.