Early in the spring of 479 the news came through that the Persian fleet, a large part of which had wintered at Cyme in Ionia, was assembling at Samos. It looked as if a sea-offensive might yet be mounted to combine with the advance of Mardonius’ army. It was, however, nothing like the confident armada that had surged through the Aegean the previous year. Samos, with its two great harbours, was an ideal place for assembling a fleet to strike westward across the Aegean, but this was a demoralised and depleted assembly of ships, no more than 300 in all according to Herodotus. It seems that one reason for its presence on the island was to keep an eye on the Ionians as much as anything else. After the reverses at Artemisium and the defeat at Salamis the heart had gone out of the principal constituents of the Persian naval arm, the Egyptians and Phoenicians, who would seem to have returned to their own countries once the army had been transported across the Hellespont, and to have taken no further part in the war. Most of the sailors and oarsmen of the fleet at Samos were probably Ionian Greeks, but to make sure of their trustworthiness they carried Persian marines aboard and were commanded by three Persian admirals, each one, presumably, being in charge of a hundred ships.
There had indeed been an abortive attempt at a coup on the island of Chios, the plot being betrayed by one member of a seven-man junto. The other six managed to escape and made their way to Aegina where the Greek fleet was assembling under the supreme command of yet another Spartan, King Latychidas. They informed him that all Ionia was ripe for revolt, that the Persian fleet was demoralised, and urged him to attack Ionia. Whether this would have been wise or not, the fact was that the Greek fleet which had assembled that year was only a third of its previous size, no ships, and was therefore of an essentially defensive nature. Athens was now dominated not only by the hoplite party, but also by the very necessary requirements of land defence. It is clear that her contribution to the Greek fleet was little more than nominal, and she had mobilised 8000 hoplites ready for the attack that must inevitably come from Mardonius in the north. There was another good reason why the Athenians may have decided to keep a large part of their fleet laid up. It was the only card they had to play against the Peloponnesians who, apart from working hard on the defences of the Isthmian wall, showed no signs of sending their army to Attica. If the Spartans and their allies would not come to the help of Athens on land, then the Athenians must look to their own defence and not dissipate their men and energies on the sea.
Late in the spring of that year, after Alexander of Macedon had returned with the Athenian rejection of the Persian proposals, Mardonius began his march south. The spring rains were over and it was time to give these insolent Athenians a second lesson, before moving on to break the resistance of those in the Peloponnese -which largely meant the Spartans - and hand all Greece over to his king and lord, with himself presumably becoming the satrap of the land. The Thessalians, who had long accepted that they were part of the Persian dominion, were naturally pleased to see him gone. It was not only that their leading dynasties were totally committed to the Persian cause, but they must have been eager to see his army eating elsewhere. The attitude at Thebes was different. The Thebans hated the Athenians, and undoubtedly saw themselves, in the event of a Persian victory, as being the natural leaders of the new Grecian kingdom which would be established under Persian control. They did their best to persuade Mardonius to make their city and their country the command headquarters for the campaign and to break up the Greek unity (which had never really existed) by bribing one city and another in the Peloponnese not to support the Spartans. ‘Send money to the leading men in the various towns’, they said, ‘and by doing that you will destroy the unity of the country, after which you will easily be able, with the help of those who take your part, to crush those who still oppose you.’ Mardonius was not of their opinion. He wanted to present Xerxes with a fine military victory, to reoccupy Attica, level Athens to the ground, and then, perhaps, make use of the Great King’s money to destroy the Peloponnesians. He was a politician, true, but he was above all a soldier and it was as such that he wished to be able to give his lord the rich prize of Greece. He had gone so far as to arrange a chain of beacons through the Aegean islands, so that the news of the second occupation of Athens could be signalled across the sea, whence the Persian couriers would take it swiftly to Xerxes in his palace at Susa.
King Latychidas meanwhile had advanced with his depleted fleet down into the Cyclades, but does not seem to have dared to move farther east than the sacred island of Delos. Similarly, there was no aggressive movement by the Persian admirals on the far side of the Aegean at Samos. At this point in the year, the enemy fleets did no more than glare at each other - and somewhat uneasily at that. The opening moves on the great chessboard of 479 were standard, and even fumbling. Mardonius moved south; the Athenians, receiving no support from the Peloponnesians, withdrew from Athens for a second time; Mardonius reoccupied Athens. One thing which the unimpeded march of the Persians forced upon the Athenians was the reactivation of their fleet which, clearly, they were not going to leave behind to be burned. This now meant that the Greeks were potentially far stronger at sea than the Persians, but it also meant that in their diplomatic battle with their Peloponnesian allies the Athenians had lost a valuable bargaining piece. They no longer held the trump of a fleet ‘in being’, which they had been able to play against the Peloponnesians’ refusal to move beyond their Isthmian wall.
At this desperate moment in the fortunes of the Athenians, withdrawn again to Salamis, while Mardonius prepared to level their partly rebuilt city to the ground, the latter, shrewdly assessing the situation, sent over to Salamis a Greek from the Hellespont area as an envoy. He offered the Athenians yet again the same terms as Xerxes had previously given them: generosity itself, on the surface, since their land was once more occupied and their beloved capital in his hands. There is absolutely no doubt that the iron determination of the previous year had deserted some of the Athenian councillors. One of them, whose name has come down to us in different variants (possibly because the later Athenians were unwilling to commemorate the event), who spoke out in favour of accepting the Persian proposals, was lynched on the spot. This was far from typical of Athenian behaviour - even less so, if one credits the tale, was the subsequent stoning of his wife and children. The envoy, Murychides, who witnessed this alarming scene, was allowed to return unharmed to his master with oral and visual evidence that the Athenians still totally rejected the overtures of the Great King.
Two separate missions in the subsequent weeks were sent off to Sparta, both, in differing degrees, bearing the same message: unless the Spartans were prepared to march north and defend Attica they would very soon find themselves left totally alone. Although the various historians are silent on the subject, one might possibly conclude that the threat made by Themistocles the previous year was never entirely absent from their allies’ minds. The people of Athens, and only they, still had enough ships to withdraw a large part of their population from Salamis and Troezen, and found a new city in the rich, comparatively unpopulated lands to the west. Sicily and southern Italy always presented them with an option - ‘O my America! my new-found-land.’ The Spartans, the other Peloponnesians, even the citizens of mercantile Corinth, did not have sufficient shipping to offer their people a large-scale evacuation. The envoys returned exasperated. The Spartans, who were far more religious for superstitious) than the Athenians and who could in any case at that moment still afford to indulge in formalities, were celebrating the Hyacinthia; a summertime festival, deriving very probably from the eastern Attis/Adonis rituals. Herodotus comments that ‘the people were on holiday and thought it most important to give the God his due’. He adds, which seems far more significant: ‘It also happened that the wall they were building across the Isthmus was almost finished and about to have the battlements put on.’
There can be no doubt that there was some hard bargaining, even threatening, at the various meetings which took place. The Spartan Ephors kept quibbling and fobbing the Athenians off with promises to let them have a decision on the following day, and so on. It was not until after the Athenian envoys had given up in disgust, and were on the point of leaving yet again, that the Ephors seem to have rethought the whole situation. One of the principal advocates of responding to the Athenian call and marching north was Chileus, an important citizen of Sparta’s neighbour, Tegea, who appears to have commanded considerable influence among the ruling class in that strange state. Having heard from the Ephors that the Athenians were again bringing up the threat of forming an alliance with the Persians under the conditions that Xerxes offered them, he pointed out the grim reality of the situation, saying: ‘As I see it, gentlemen, if the Athenians desert us and make an alliance with Persia, then, however strongly the Isthmus is fortified, the postern gates are wide open for the Persian invasion of the Peloponnese. So you had better listen to them before they change their minds and adopt a policy which will ruin Greece/ In this, of course, he was absolutely correct. Without the aid of the Athenian fleet the Isthmian wall would have become as redundant as did that of Maginot centuries later. It would merely be bypassed and the Athenians would land the Persian army wherever they wanted in its rear.
After prevaricating for so long, the Ephors now acted with haste. Almost overnight 5000 Spartiates, out of what was probably a total of 8000, were mobilised and on the march north. With them, according to Herodotus, went 35,000 Helots. These would have been lightly armed troops, but good fighters none the less, as they had already proved at Thermopylae. One reason for taking such a large number of Helots was possibly the fact that, with the bulk of the Spartiate army on its way out of the country, the Ephors did not want to risk any chance of a Helot uprising. In any case the Helots, too, could see that Persian victory would not improve their position but would turn them into total slaves under the Persians and their sympathisers. Pausanias was put in charge of the whole campaign, his cousin King Pheistarchus, the son of Leonidas, being only a boy. Pausanias was himself only in his twenties but he had great strength of character, as he was to prove, and had probably from the very start been one of those who advocated an active policy as against the more conservative Ephors.
The speed of the mobilisation and of the Spartan army’s march to the Isthmus was such that, even if the Argives ever had any intention of fulfilling their promise to Mardonius to stop any Spartan move to the north, the Spartans were already passing their frontier. It is difficult to believe, in any case, that, faced by such a weight of men, Argos would have dared to take any action. They did, however, send a runner with a message to warn the Persian commander that ‘the fighting force of Lacedaemon is on the march, and that the Argives have been powerless to stop it’. One can only presume that this young Argive bypassed the Isthmian line in a small boat before making his way to Mardonius. All the members of the Spartan league mobilised with almost similar swiftness and marched to join Pausanias at the Isthmus, only Mantinea and Elis were too slow in moving and missed the campaign that was to follow. Mardonius now knew there was no doubt that a large Peloponnesian force combined with the Athenians portended a battle which, even with his numerical superiority, was going to be a hard one. He knew how only 300 Spartiates with a few thousand behind them had held up the full weight of the Great King’s army at Thermopylae.
Athens and Attica must again be abandoned and he must fall back on Thebes, where the territory around the Asopus river would afford him the chance to deploy his cavalry in good measure. At the same time, as he knew from the Thebans who had already suggested that he make their city his base, he would have pro-Persian allies whose greatest desire was to see Athens permanently destroyed. Before he left the city he once again sacked as much of it as he could, even though the time-factor prevented his demolition teams from leaving the site as barren as he would have liked. Attica itself, however, was once again ravaged. Mardonius, like any intelligent general, had no intention of leaving food and fodder for an army that was clearly intending to advance against him, and not just hold a defensive position on the Isthmus. For the first time, perhaps, he must have felt more than a twinge of unease. He had failed to divide these two principal Greek states. He knew about the calibre of the Greeks, and in particular the Athenians, at sea; and he knew about the Spartans’ prowess on land. The beacons had signalled from island to island across the Aegean the second capture of Athens and of all the Attic land. He was a close blood relation of Xerxes, but that did not count too closely in an autocracy where the title ‘King of Kings’ literally meant what it said.