Immediately after the defence force had taken up their position, Leonidas had set about the necessary tasks of a professional commander. While the old Phocian wall was being reconstructed he had two main objectives: first, to secure his supply-lines and, secondly, to deny the land immediately to the north of Thermopylae to the enemy. Between the pass and the city of Lamia, through which Xerxes must pass in order to attack him, there lay a fertile plain. It was practical to raid the farms, homesteads, and granaries in the area - and it was practical to do so at night so that the unfortunate locals and the people of Lamia would not be able to see how small was the force that lay in the track of the great army. Leaving the wall behind them, the troops moved up past the West Gate and spread out into the plain. Presumably, since there was as yet no threat to his position, he took nearly all his men with him. In a night that ruined many a farmer (war spares no one) granaries were emptied, buildings set afire, and even the trees were cut down. Let the lights and the noise and the shouting be heard in Lamia, and let its citizens report in due course to the Persian king that the famous Spartans were waiting to receive him! The raid had, of course, its practical aspect since cattle were driven back to their base, grain was always welcome, and a scorched-earth policy - even if only over this limited area - meant that the advance units of the enemy would find no comfort on the land. For his main supply-base Leonidas had the village of Alpeni behind his lines, but the raid enabled him to establish a useful and immediate supply-dump at the Phocian wall itself.
The other immediate consideration was the security of his chosen position. All passes can, in the end, be turned. Their ten-ability, even for a temporary holding operation, rests entirely upon the length of the detour that the enemy will have to make before he can circumvent the defence and take the opposition in the rear or -quite simply - bypass the defenders and march forward. Leonidas, like Themistocles, had shown that he rejected the Isthmian Line thinking of so many of the Peloponnesians, and had proved it by his willingness to march all the way from Sparta to this lonely pass in the north. The very name of the mountain which protected the landward flank of the Spartans was a clue in itself to a weakness in the Thermopylae position. Kallidromos means ‘Beautiful Running Track’. Now it is true that such a name might well be applied by local inhabitants in jest, or even in the sense of placating a formidable place. (Just so the Sicilians who inhabit the fertile but ever-dangerous slopes of Mount Etna to this day call it ‘The Beautiful Mountain’ - more to conciliate the volcano than to show their aesthetic appreciation of it.) Herodotus does not use the name Kallidromos, though at a later date the great geographer Strabo does, and one senses that it is an old local name and that it had a meaning. For Kallidromos does provide a beautiful track.
‘[It] was originally discovered’, Herodotus writes, ‘by the Malians of the area. Later they used it to help the Thessalians, leading them over it to attack Phocis at a time when the Phocians had built themselves a wall across the pass to protect themselves from invasion.’ (My italics.) It had long been known, then, that the Phocian wall which Leonidas and his men had just rebuilt and reinforced could be bypassed comparatively easily. The men of Phocis who were serving with Leonidas knew all about this route, and so of course did the Malians. The latter were about to be overrun by the Persians, and they had no cause to love the Spartans. Herodotus comments: ‘So, for a long time, its treacherous use had been known to the Malians. The track begins at the Asopus, the stream which flows through the narrow gorge. The track itself, like the mountain, is called Anopaea. It ends at Alpenos, the first Locrian settlement after one leaves Malis.’
Kallidromos, in fact, as its name suggests, was not a spiny ridge of rock (such as one might expect from a casual inspection), but along its crest there run two parallel ridges, between which lies a narrow but fertile mountain plain which at that time was fringed by dense oak forests. It was of course impossible that Leonidas should not know about this for, even if as a man from the Peloponnese he had no personal knowledge of it, his Phocian allies would have been the first to tell him of its existence. The indictment of the Greek Ephialtes (a man from Malis as one might expect) by ancient and subsequent modern historians, as the Judas who betrayed the Spartans and the Greek cause is over-severe. Indeed, one or two other names were traditionally given as the name of the guide who led the Persians over the mountain. The fact is that even if it was a man called Ephialtes, which one may accept, there were others who could have shown the Persians the way. Most shepherds, local farmers, or mountain men could have done so. The great secret about Thermopylae and ‘the selling of the pass’ is that there was no secret.
Leonidas naturally would have been the first to hear about it, and he did what one expects any commander to do. He realised at once that, since he could not abandon Thermopylae, which he had been entrusted to guard so as to maintain the strategic line with Artemisium and the fleet, he must set a watch-dog on the path that outflanked his position. Ideally, he would have chosen for such a role a Spartan contingent - men trained from childhood in war, in tracking down subversive Helots in their hideaways, men who could hear in a rustle of grass the passing of a potential enemy, and men men who had consecrated themselves by the laws of Lycurgus to stand and die. (‘Come back with your shield or on it,’ as the Spartan mother is said to have told her son.) Unfortunately, because he had no more than his 300 chosen Spartiates, Leonidas could not afford to deplete the ranks of these trained professionals who would have to stand and face the army of the Great King, and who would have to officer their mixed allied force - men of uncertain training whose morale and discipline could not necessarily be relied upon. Leonidas has been criticised, with the benefit of hindsight, by later historians for not having sent a Spartan contingent to guard the pass over Kallidromos, or at least for not having sent a Spartan handful to ensure that the leadership was resolute. It is difficult under the circumstances to see that he could have done other than what he did: he sent back the Phocian contingent, 1000 strong, to take up a position where they could deny any enemy the passage long enough for the news to get through to Leonidas that the well-known route over the mountain was being used. The men of Phocis were familiar with the area, had known it for many years; they had shown themselves resolute enough to be prepared to join this Spartan advance guard and face the overpowering enemy from the East. The real trouble was to stem from the fact that ‘the dog did not bark in the night’.
That darkness was approaching. At about the same time as the capture of the fifteen triremes by the allied Greek fleet, the head of the Persian army was forming up in Lamia. Many historians (mostly study-bound men until this century) have written about armies just ‘arriving’, but armies in any century - even in the mechanised war-bedevilled one in which we live - take some time in which to arrive. Scouts must go ahead, followed by fast and lightly armed troops, a crack spearhead, and then in turn the main -however disciplined - somewhat amorphous body, followed in its turn by commissariat, baggage-train, pack animals, and sundry followers. The bulk of the army of the Great King most probably advanced in two columns, one along the coastline and the other going inland by the Othrys mountain-route. The arrival of Xerxes near Trachis between the rivers Spercheius and Asopus, and the fact that he stayed there for four days before any attack on the Thermopylae position developed, means little more than that the king and his staff were waiting for the main body of the army to come up and regroup. The first to arrive on the scene will have been the advance guard of cavalry (Herodotus says ‘one man on horseback’). Xerxes now knew that it was the Spartans who were holding the pass against him, but it is likely that he knew that it was not the Spartans alone but a mixed force of Greeks. Perhaps Demaratus, who will certainly have heard that Leonidas was at their head, may have assured him that it could not be the full force out of Sparta as this would not be permitted by their strict laws until after the festival of the Carneian moon?
Like any sensible commander-in-chief Xerxes determined, even at this last hour, to try a divisive and conciliatory policy. According to Diodorus, but no more than hinted at in Herodotus, Xerxes sent heralds to the Greek lines to tell the defenders of the pass that if they laid down their arms they might depart in safety. More than that, the Great King assured them that if they did so they would be considered as allies of the Persians and would be rewarded with far richer lands than those they now possessed. It was hardly surprising that this tempting offer produced some division and argument in the Greek camp, but one must take leave to doubt that these heralds were ever allowed behind the Phocian wall. If they were, indeed, ever sent, they would certainly have been met by a Greek delegation in the pass. Leonidas could never have been so foolish as to allow any Persians to see quite how small was the force that stood waiting to oppose them. It would seem that ‘the Peloponnesians’, from whom one can safely exclude the Spartiates, were in favour of the old idea of falling back and holding the Isthmian wall. ‘Leonidas’, it is categorically stated, ‘said that they must stay where they were. But at the same time they must send an appeal to all the states in the confederacy to despatch reinforcements, as their own numbers were inadequate to cope with the Persians.’ The men of Phocis and of Locris very naturally were in agreement with the Spartan king, for it was their lands and their cities which would be devastated by the enemy if northern Greece was abandoned. Xerxes’ offer was rejected.
Herodotus now tells the story which, famous though it is, must be repeated yet again for the brilliant light which it throws upon a small but significant moment in human history:
During the conference Xerxes sent a horseman to find out the strength of the Greek force… . The Persian approached the camp and made a survey of all that he could see [evidence enough that the heralds were never allowed behind the Phocian wall] and to observe what the soldiers were doing. This was not, of course, all the Greek force, for he could not make out the troops behind the reconstructed and guarded wall. Nevertheless, he took careful note of those troops who were stationed outside the wall. At that time they happened to be Spartans, some of whom were stripped for exercise while others were combing their hair. He watched them in astonishment and took due note of their numbers, and then rode back at leisure. No one attempted to pursue him and indeed, no one took the slightest notice of him.
This truly ‘laconic’ behaviour must have astounded the Persians even as much as it did the Great King when the horseman came back into his presence with his report.
Demaratus cannot have failed to be concerned on hearing that a Spartan force under Leonidas was holding the pass. The latter was no enemy of the exiled king and, although Demaratus hoped to regain his throne and save Sparta through his friendship with the Persian monarch, he cannot have wanted to be responsible for the annihilation of a force composed of Spartiates. Not only did he know Leonidas but, in that small world of the unwalled city to the south, he will have known all the men, or the families of all the men, who were now (so casually, it seemed to Xerxes) preparing themselves to die in battle. Perhaps it could be avoided? He is already supposed to have sent a secret message to Sparta, warning his people of the time of the invasion - a message which passed like uncensored mail through the Persian lines because its real contents were written on the wooden tablet below the wax, where normal letters were inscribed. (This hidden message is said to have been discovered by the clever wife of Leonidas himself, bright-eyed
Gorgo.) When asked by the king who were these men outside the wall in the pass, Demaratus told him that they were Spartans. He cannot possibly have hoped to weaken the king’s determination to invade Greece, but it is just possible that he may have tried to make his kinsmen sound so formidable that Xerxes and his staff would decide to leave them alone and make a detour round Thermopylae. In any case, he owed it to himself as their former king to make them sound as awe-inspiring as possible - and therefore most useful allies after his restoration.
Whatever his sources for this episode, Herodotus produces a very convincing speech by the exiled and unhappy Spartan king. ‘On a previous occasion,’ Demaratus said, ‘you have heard me talk about these men. I told you at the time how this venture would turn out.’ (The wreck of a large part of the Persian fleet may have served to give him an uneasy feeling of disaster.)
My Lord, I only try and tell the truth when in your presence. You mocked me before, but please hear me again. These men are making ready for the coming battle and they are determined to contest our entrance to the Pass. It is normal behaviour for the Spartans to groom their hair carefully before they prepare themselves to face death. I can reassure you on one point: if these men can be defeated and the others of them who are still at home, then there is no one else in the whole world who will dare to lift a hand, or stand against you.
The Great King smiled. What was a small stone wall to a ruler who had bridged the Hellespont and driven a channel for his ships through the land behind Mount Athos? What was a scuffle of dust across a small plain to disturb the ruler of the greatest empire that the world had ever known?