Xerxes and his staff had calculated that it would take the army some fourteen days to get itself down to Thermopylae. The fleet on the other hand, moving from the Thermian Gulf to that of Pagasae, could do the journey in two to three days. The fleet was therefore instructed to stay where it was for eleven days after the king’s departure and then get under way for the rendezvous. If Xerxes
and his staff, after all their elaborate preparations over the years and in all their efficiency on the march itself, had erred, it was in ignoring the time element. Once they had got themselves across on to the mainland of Europe there seems little evidence that they had made any great haste. Indeed, such evidence as there is suggests that Xerxes, enjoying his triumphal progress, had dallied too long. It is true that in places the nature of the terrain had delayed them (necessitating road-building, for instance), but even now, when his scouting squadron had returned with their news and he knew that the Greeks were awaiting him, he seems to have dallied. While in Thessaly he held races between his own Persian horses and the local breed, and was delighted when the Persians triumphed every time, for he had been assured that the horses of Thessaly were the finest in Greece. This seemed a good omen. In Achaea he found time to listen to local story-tellers and even diverted the army slightly to avoid a piece of ground which he had been told was sacred.
The admirals and captains of the Persian fleet may well have wished that the army could move a little faster (often a bone of contention between other navies and armies in many later years). None of them can have been ignorant of the fact that they were now into mid-August and that it would be late in the month by the time that they set sail. Even in those days without charts, written information or instruments, weather lore, transmitted orally over many centuries, will have been almost as accurate as anything that can be found in a modern Pilot for the Aegean. When vessels were relatively frail and very largely dependent upon manpower, weather conditions were all-important and none of the master-mariners in the Persian fleet can have been ignorant of the fact that, although sultry high summer was still with them, it could break at any moment. Hesiod wisely set the limit of the sailing season for sensible men to fifty days after the summer solstice. Even though the Egyptians, for example, may have been ignorant of Aegean conditions it is impossible that the Greeks from Ionia and the islands or the Phoenicians who had known the sea for centuries cannot have been aware that they were about to set out down a singularly inhospitable coast at a time in the year when the weather is likely to become unstable. Under the grande chaleur of summer all the Aegean has been gradually heating up and it requires no more than a slight change in barometric pressure to produce an imbalance. When this happens the hot air rises suddenly over the sea, lifting like a great balloon, and the cold air from the north roars down to replace it. The Delphic oracle (though often misleading and confusing) was at the same time the repository of most of the knowledge - including meteorological - of its time. ‘Pray to the Winds’ had been the last counsel given to the seemingly doomed Greeks. The Athenians accordingly offered up prayers to Boreas, God of the North Wind.
The Persian fleet sailed on time as ordered and, after one day’s voyage out, ‘they were off the part of the Magnesian country between Casthanea and Cape Sepias. On arrival the leading ships made fast to the land but, as there was not much room on the small beach, the remainder came to anchor and lay facing offshore in lines up to eight deep.’- All had gone well so far, but many of the captains, except for those who had arrived first and managed to beach their ships, had good reason to feel uneasy at their exposed position, but still they could remind themselves that twenty-four hours would see them in safety. ‘At dawn next day,’ Herodotus continues, ‘the weather was clear and calm… .’
It was that curious bright stillness which often precedes the onset of a violent north-easter. A ‘Hellesponter’ was then the Greek word for it, while today it is known as the maistro, the ‘master wind’. It can come raging out of a cloudless sky without warning, as the hot air lifts soundless to the south. (Even the modern barometer can be too slow to catch any advance changes in the air pressure.) As often as not there are no forewarning signs - no banners of cirrus or altostratus, nor any premonitory swell in advance of its coming. So it was on that day when the Persian fleet was getting under way and preparing to move on down the coast. Suddenly out of the north the wind began to pour in gale-force fury. The Persian fleet was caught on a lee shore.
Herodotus continues:
Those who realised in time that the blow was coming, and all who happened to be lying in a suitable place, managed to beach their vessels and get them hauled ashore before they were damaged and before they lost their own lives as well. The ships which were caught offshore, on the other hand, were all lost: some being driven down onto the place called the Ovens at the foot of Mount Pelion and others onto the beach. A number ran aground on Cape Sepias itself, and others again were driven ashore off the cities of Meliboea and Casthanea. It was a storm of the greatest violence.
The Athenians had prayed to Boreas and the god had obliged them. Herodotus maintains that the Persians lost ‘four hundred ships, at the lowest estimate’. This, like his figures for the fleet itself, would seem to be an exaggeration. That they lost a great many is almost undeniable, as anyone who has seen that harsh coast can easily imagine. (It would be hard going to claw off it even in a well-found modern sailing boat under northerly gale conditions.) Awkward, oared triremes, with only a squaresail, would have been extremely difficult to extricate from such a lee shore and there can be no doubt that the loss was severe. Perhaps a quarter may have been destroyed, but a loss of 400 fighting vessels would have amounted to nearly half of the front-line fleet: something which would have been unacceptable and which would have led to the abandonment of the naval campaign. The fact that the Persians regrouped, made good their storm damage, and later proceeded relentlessly on their way does not suggest a shattered fleet. The gale lasted unabated for three days - a long blow for August when such storms, though fierce, are usually over in about twenty-four hours. (At a later date the Athenians remembered how Boreas had answered their prayer and built him a shrine by the River Ilissus.)
It is clear that the Greek allied fleet sat out this storm tucked well under the lee of Euboea, so Herodotus’ statement that they went as far south as Chalcis may not be wrong, although they need not have gone anywhere near as far away to find a good lee under the island. One suspects that they went a little south of the latitude of Thermopylae and then took shelter close under the western coast of Euboea. Green, however, believes the Herodotean source and thinks that Themistocles deliberately went down into the narrows by Chalcis in the hope of inducing the Persians to follow. They would then have found themselves in unfamiliar, constricted waters, where their numbers would not have been able to tell, and where the slower but heavier Greek triremes could have done to them what they were, indeed, later to do at Salamis. This is quite possible, but what is really significant is that the ‘Hellesponter’, which did such damage to the invasion fleet, left the allies completely untouched.
Even before the storm had blown itself out the Greeks had informed reports of the destruction of a great number of the enemy from their watchmen in northern Euboea. No doubt much wreckage was coming down on the great rollers past Cape Sepias and through the channel between Skiathos and the neighbouring island of Skopelos - an area known for good reason to this day as the ‘Gate of the Winds’. ‘On hearing the news, they offered prayers of thanksgiving and libations of wine to their saviour Poseidon and made all speed back to Artemisium in the expectation that there would be few ships left to oppose them.’ In this they were to be disappointed for, as they headed north for their station, they could see great numbers of ships rounding Cape Sepias and turning up into Aphctae just within the Gulf of Pagasae. It is possible that if they had been quicker in their return or had not lain so far away they could have caught the main body of the Persian fleet at this point and provided the battle that Themistocles sought. As it was, they did have one piece of luck, for fifteen stragglers coming up behind the main body mistook the Greeks for their own fleet and made to join them - only to be rounded up and captured. Since they were a mixed squadron, some of them Ionian Greeks whose triremes would have been almost identical, it is not so surprising that this mistake took place. One of the captains, who was from Paphos, admitted during interrogation that out of twelve ships from his Cypriot squadron eleven had been lost in the storm off Sepias. Greatly heartened by this news, and by the general picture that they obtained of the storm-battered condition of the enemy fleet, the allies sent back all the prisoners to their headquarters at the Isthmus of Corinth.
At the time of the great storm, the Spartans and their allies had been consolidating their position at Thermopylae. Placed as they were in that narrow pass close to the sea’s edge even the most unobservant of landsmen could not have escaped noticing - and feeling - the cut of the wind and the roar of the sea. They knew that the Great King was coming, for some of the wrack of his advancing fleet must have siphoned past the north of Euboea and been reported. The gale will have struck their narrow ledge of land and hurled upwards over the mountain that protected their inboard flank. Spray will have splattered over the sea-edge, the cauldrons with their flames will have had to be protected, and the scarlet fighting cloaks drawn close over the waiting men.
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.’