Admittedly, the Argives, playing hard to get, had not yet openly committed themselves to the cause of the Great King. Nor, however, as the Spartans were all too painfully aware, had they pledged themselves to the allies. When representatives from Sparta, arriving in Argos that winter, had invited them to do so, the Argives had responded with what they knew were impossible demands: a thirty-year truce and a share of the command. The negotiations had collapsed on the spot. The Spartan ambassadors, frog-marched to the border, had been warned that any repeat of their mission would be interpreted as a hostile act. “For rather than concede so much as an inch to them, the Argives would actively prefer barbarian rule.”65
A statement of neutrality that appeared, to the Spartans, quite as menacing as a threat. Even before the allies’ first conference at the Hellenion, they had suspected the worst of Argos—and with good cause. While the Argives, in justification of their inglorious fence-sitting, could brandish a warning from Delphi advising them to “look after yourselves and keep your spears locked away,”66 the Spartans, “at the first stirrings of the war,” had also applied for a long-range forecast from Apollo. The Pythians, returning from the oracle, had brought their royal masters, Leonidas and Leotychides, a most alarming message.
Your fate, O inhabitants of the broad fields of Sparta,
Is to see your great and famous city destroyed by the sons of Perseus.
Either that, or everyone within the borders of Lacedaemon,
Must mourn the death of a king, sprung from the line of Heracles.67
Food for thought indeed. It was not merely that either Leonidas or Leotychides appeared to have been given a death sentence; there was also, in the description of the apocalypse that would otherwise overwhelm Sparta, a sinister, and typically Delphic, ambiguity. Who precisely were the “sons of Perseus”? The Persians? The Argives? Both? That the allies’ spring conference was being held at the Isthmus, midway between the Peleponnese and northern Greece, would only have served to make the question more alarming and pressing yet. Ahead of the ambassadors, far distant on the frontiers of Asia but drawing ever closer by the day, the Persians; behind them, eyes presumably fixed brightly on their backs, the Argives: sons of Perseus both. It was scarcely surprising that the Spartan delegates were jumpy.
Whether Leonidas and Leotychides were among them, we do not know. It was not normally the practice of Spartan kings to act as their own ambassadors, but Leonidas, in particular, as representative of the senior royal line and therefore the allied supreme commander, would surely have wished to keep track of new intelligence in person. If he did attend briefings at the Isthmus, however, he would have found it a singularly discouraging experience. Despite the high hopes of the previous autumn, no new allies had committed themselves. Just as Argos had done, many of the states that had been approached had explained that Apollo was advising them to keep their heads down. The biggest disappointment of all was the man who had attracted the giddiest hopes: the tyrant of Syracuse. Gelon, who desperately needed every last ship and soldier for his own looming showdown with Carthage, but did not wish to lose face by admitting as much, had extricated himself from his commitments to the old world by trumping even the Argives for impudence. First, he had demanded exclusive command over all the Greek forces; then, making a great show of compromise, over either the army or the fleet. When the allied ambassadors, just as they were meant to, had refused these terms indignantly, Gelon had snorted in contempt: “You seem to have no lack of leaders, my friends—all you need now is to find some men for them to lead.”68
A withering put-down—and one that appeared to have dealt a fatal blow to any notion the Greeks might have had of staging an amphibious holding operation. While an army of hoplites, if they could find a suitable mountain pass to blockade, might still conceivably hope to keep the barbarian hordes at bay, most delegates felt the allied fleet, deprived of Gelon’s two hundred triremes, had no hope now of engaging the Persians on equal terms. Themistocles, of course, profoundly disagreed; but he was having trouble, that spring, in keeping even his own fellow citizens on board. The Spartans were not the only people to have passed a twitchy winter. The Athenians, having spent a fortune on their new fleet, and much time and effort, were having second thoughts about their whole strategy. Many were steeling their nerves for the ordeal ahead with a renewed nostalgia for Marathon. The closer the Great King drew, the more the veterans who had triumphed in that celebrated victory—the doughty, obdurate, conservative hoplite class—itched to smash their oars over Themistocles’ head and have another crack at the barbarians on land. Themistocles himself, who had hoped this particular chimera had been slain with Aristeides’ ostracism, had almost been dismissed from his command. Only by bribing his rival for office to stand down had he scraped through in the annual elections to the board of generals. His authority was ebbing—and his enemies in Athens knew it. So too did his fellow delegates at the Isthmus. Themistocles, for the moment, was in no position to throw his weight around.
Instead, amid all the drift and despondency, it was left to a posse of cattle barons, sun hat–wearing bull-wrestlers from Thessaly, to seize the initiative. Arriving unexpectedly at the conference, they urged the downcast allies to look to the north. Alarmingly flat and spacious though Thessaly was, and therefore ideal for the Persians’ cavalry, its rolling fields were surrounded on every side by mountain ranges, superlative natural bulwarks looming upward from the dusty plain. Of these, the most imposing by far lay to the north, along the border with Persian-held Macedon. Here, the Thessalian barons urged, the allies should make their stand. The delegates were intrigued. To many of them, instinctively parochial as most Greeks were, Thessaly was terra incognita, not merely remote but positively sinister, as famous for its witches as for its livestock or corn—yet everyone had heard of Mount Olympus, of course, and its immediate neighbor, Mount Ossa, two of the mountains that defined its northern border. Many delegates would also have heard of Tempe, the narrow five-mile pass that separated Olympus from Ossa, its walls so sheer that only Poseidon’s trident, it was generally assumed, could possibly have shivered the cliffs apart. The Thessalians assured the allies that any army heading south would have to pass through this gorge: all the Greeks needed to do to halt the Great King in his tracks was dispatch a force to Thessaly and stopper Tempe up. It appeared a foolproof argument. Even the Spartans were convinced; and this despite the fact that the plan would oblige them to send troops perilously far from their comfort zone of the Peloponnese. Ten thousand hoplites, from a variety of cities, were marshaled for the journey: the same number, perhaps significantly, as had seen off the barbarians at Marathon. A Spartan, naturally, one Euainetus, was put in overall command. The Athenian contingent was led by Themistocles.