The withdrawal from the Pass of Tempe provided the background to the thinking of the League Congress when it met for the last time before ‘the thunder of the chariots in the north’ had made itself ominously heard. It was hardly surprising that the return of the hoplite force had resulted in the immediate defection of nearly all the northern Greek states, especially Thessaly and Boeotia, which now saw themselves as having been abandoned. Alexander of Macedon had long ago made his choice, for he had seen from the beginning that, if the Persian host was held up on his territory by a delaying action, it would strip his own land barren. Better by far that they should pass swiftly through Macedonia.
It seems astonishing that even at this late hour the spokesmen should have been bickering and politicising (but modern Greeks under somewhat similar circumstances have done so to this day). Athens had earlier made the greatest concession of all: she had agreed that her fleet should come under the over-all command of a Spartan. Since Athens represented by far the greatest naval power in Greece, her action in doing so was admirable - even if it was largely forced upon her by the fact that the Peloponnesian allies would not accept an Athenian in charge. Themistocles most probably made this concession because he knew that, in the end, it was his strategy that would have to be adopted, and that the size of the new Athenian fleet in comparison with the composite numbers of the Spartan and others would, when it came to action, determine the tactics. ‘Realising that if they quarrelled about the command, Greece would be lost’, Athens (which almost certainly means Themistocles) was prepared to swallow her pride.
Most of July was wasted… . The Spartans, in particular, had their usual religious objections to campaigning at such a season. Their chief festival, the Carneia, fell on or about 20 August, at the time of the full moon; so, that year, did the quadriennial Olympic Games, during which all warring Greek states sank their differences and competed together in relative friendship.
As had been said before, although these religious, or quasireligious, obligations may seem odd to a modern, they were far from so to an ancient Greek, who lived in a world surrounded by totems and taboos that often obfuscated his thinking. One definitely rational piece of thinking that had marked the Athenian decisions promoted by Themistocles was to recall those who had been exiled under the system of ostracism - although possibly not to home itself, but only to the island of Salamis. It seems clear, at any rate, that in her hour of need Athens was prepared to use all the brains that she could summon - even if they were hostile to the man or party in charge. Aristeides responded (as might be expected from what one knows of his character) and so did Xanthippus. Hipparchus, on the other hand, had joined the ‘Quislings’, who sought their future with Xerxes and looked for revenge - and power -when both Athenians and Spartans were beaten into the ground.
Old Artabanus in the wise counsel that he had given to Xerxes -and for which he had been sent back home - had summarised the problems which would follow upon an invasion of Greece. Since the Greeks clearly thought along the same lines, and since their thinking determined their strategy in the face of this apparently overwhelming threat, his words, as given by Herodotus, are worth repeating:
I warned your father - my own brother Darius - not to attack the Scythians, those nomads who inhabit a land without cities. He would not listen to me. Quite confident that he could overcome them he invaded their land. Before he returned home many brave soldiers who had accompanied him lay dead. But, my lord, you intend to attack a nation infinitely superior to the Scythians: one with a reputation for immense courage, both on land and sea… . The Greeks are reputed to be great fighting men - something one can well judge from the fact that the Athenians on their own destroyed the large army that we sent against them…. I strongly urge you to abandon this plan.
Artabanus’ advice was based sensibly and primarily upon logistics. The Persians would be far from home, their lines of communications extravagantly extended, and, as he reminded Xerxes, ‘God tolerates pride in no one but himself. It is always the large buildings and the tall trees that are struck by lightning. This is God’s way of bringing the lofty to their proper level. Often a great army is destroyed by a small one… .’
The Greeks in their councils, quite apart from the formal League at Corinth, had already seen that their best hope lay in allowing the Persians to over-extend themselves. There could be no hope of defeating so vast an army in a pitched battle. However superior the hoplites had proved themselves at Marathon, this time sheer weight of numbers would overwhelm them. The Greeks had little in the way of archers and the same could equally be said of their cavalry. Their only chance lay in finding a suitable defensive line to check the invaders, for however brief a period, while the main engagement took place at sea in a position which they had carefully selected. Tempe had proved too far forward, the surrounding inhabitants pro-Persian, and their flank easily turnable. Geography determined the line which they finally decided to hold.
Greece is a mountainous country and, as Artabanus had already pointed out to Xerxes, its coast is singularly inhospitable. To the east and north of Athens the long fish-shaped island of Euboea lies like a defensive shield. Its eastern coast offers no harbours and any fleet finding this bleak shore to leeward in the event of a blow would be in great trouble. It was now high summer and, after the indecisive vagaries of the prodroms, the real ‘Greek wind’ had set in to blow. The Meltemi, as it is called, is almost as steady as the Trade Winds of the oceans. It can be relied upon throughout most of the summer to be constant from a northerly direction, as the colder air from the Black Sea and Russia beyond flows down steadily to replace the hot air which lifts over all the Aegean, the Mediterranean, and Africa. Dying away only slightly at nightfall (but still leaving a pitching and lumpy sea), the Meltemi can be expected to blow at anything between Force 6 to 8 on the Beaufort scale, at times even reaching gale force. Such conditions can render sailing difficult in the Aegean even for modern coasters, caiques, or well-found sailing boats. For the trireme, labouring under oars, and even the wind from astern, the Meltemi was hardly a friend.
Between the northern tip of Euboea and Cape Sepias on the mainland there lies a six-mile-wide strait, leading into the Euripus channel, which separates the island from Greece itself. Artemisium on the northernmost spur of Euboea took its name from a temple erected there to the goddess Artemis ‘Facing the East’, this attribute no doubt arising from the fact that it was from here that ships took their departure eastwards across the Aegean. It had no doubt been well endowed by mariners contemplating what was then a long and often hazardous voyage. North of Euboea from Cape Sepias to Mount Olympus the land presents an iron-bound coast - a wall of mountains where there is little shelter except for small craft, and certainly nothing that could remotely accommodate a fleet. The Persian armada, after they had traversed the ship-canal through the peninsula at Mount Athos and rounded the two other peninsulas of Chalcidice had a long haul of over sixty miles before they came to the strait between the island of Skiathos and Cape Sepias, with always this brooding and hostile coast on their starboard hand, threating them if a gale from the north blew up. Confronting them, as they emerged, lay Artemisium. It was plain that the key to the whole naval campaign lay here. At this point they might be held or even defeated. At the same time Themistocles, who possibly saw this in his grand design as no more than a holding action, was well enough aware that the fleet must act in concert with the land forces - as indeed must Xerxes himself. The Persian army would have to pass round the Malian gulf opposite the northern end of Euboea and here, at the Pass of Thermopylae, lay the ideal place for a comparatively small force to check a large one, which would not be able to deploy and take advantage of its numbers. Artemisium and Thermopylae, then, between them presented a geographically linked dual sphere for action.
At this late moment, ‘as the Greek forces hurried to their stations’, Herodotus informs us, ‘the people of Delphi in great alarm for their own safety and that of Greece, applied to their oracle for advice. “Pray to the winds,” came the answer, “for they will be good allies to Greece.” ’ The Delphians passed on this response to all the Greek states who had decided to fight and it gave them great comfort. Themistocles, whose strategy, as we have seen, depended to some extent on the fact that the Persian fleet would have to come down that long and formidable coast and who, like every Greek acquainted with the sea, knew what weather the winds could stir up in the Aegean must have been as comforted as any.
In the high heat of late June, having left Doriscus, Xerxes and the army marched westwards while the fleet coasted offshore headed for the Athos canal. In the coastal plain east of the River Nestus the army was able to deploy and instead of moving like a great snake could now be organised into three parallel columns. There were two marshals in charge of each column, Mardonius and the king’s brother leading the column that followed along the coastline, while Xerxes himself was in the central column, and the third and most inland column marched along the foothills that hemmed the plain. Now indeed the die was irrevocably cast as the fleet with its sweating oarsmen streamed south, and the army spread out in a broad fan over northern Greece. Nothing like this had ever been seen before, nor, in the long and strife-torn subsequent history of Greece, would anything quite like it ever be seen again.
Where the hills drew close to the sea, west of the Nestus, one Thracian chieftain showed that not all in the far north were prepared to accept this invasion of their country. He refused to give the token earth and water, and fled inland to the hills. At the same time he cautioned his six sons to have no truck with the enemy but to join him. The sons, however, were pro-Persian and, as young men, probably thought it would be both fun and profitable to join the Persian army. At a much later date, when they return home among the vanquished, they found an inexorable old man who had neither forgiven nor forgotten their disobedience - he had all of them blinded. Most of the local tribesmen, however, were more amenable and either joined the host or were conscripted into it. Only a tribe called the Sacae would neither assist nor be conscripted, ‘for they have never been reduced to subjection … living in high mountain country, well-wooded and covered with snow. They are also formidable warriors.’
Xerxes need not bother about such tribesmen in any case; they constituted no threat to his vast army, and could be left on their inclement mountainsides. Water at times still proved a problem; a small river was drunk dry, and in another place a very brackish lake (Herodotus says ‘salt’) was drained by the pack-animals. Later on a further hazard was to beset them, the animals, and in particular the camels, being attacked and eaten by lions. Herodotus suggests that the lions developed a special taste for camel meat. The fact was that the camels always came last in the advance because the sight and smell of them upset the horses, so it was natural that the stragglers should get taken. During the early stages, because of the nature of the country, the army’s progress was slow. There were no roads, pioneer corps had to go ahead and hack their way through and, where the ground was suitable, engage in proper road-building. Long after the great invasion was over, the people of Thrace still revered this Persian road and would not cultivate the land. No doubt they found it useful.
When the army reached the River Strymon at a place known as Nine Ways the pioneers, efficient as usual, had arrived well in advance and pontoon bridges had been prepared for the crossing. The excellence of the organisation, the careful planning and attention to detail, is one of the most remarkable aspects of the Persians -and would not be equalled for many centuries. Herodotus is keen to stress the superstitious and indeed barbaric nature of the invaders and their religion. After telling us that the Magian priests sacrificed white horses to propitiate the great river, he adds that, hearing the place was called Nine Ways, they took nine native boys and nine girls and buried them alive. There is something slightly suspect in this story, for human sacrifice had no part in the religion of Zoroaster (although it had in that of the Phoenicians).
Xerxes was naturally eager to see the great canal and watch his ships passing through it two abreast. He turned aside from the main route and visited Acanthus, whose citizens had been among his warm supporters and who had helped in the construction of this masterpiece of engineering. As a mark of the royal favour he made them a present of a suit of Median clothes - presumably to be worn by the head man or hung up in a temple. One minor episode marred the Great King’s pleasure in this visit and that was the sudden death of Artachaees, a notable Persian, a relative of the king, ‘the biggest man in Persia, over eight feet tali’. Renowned for his stentorian voice (always useful in a foreman!) he had been placed in over-all charge of the construction works. He was buried with great pomp and ceremony and the army heaped a large mound over his grave. He was later worshipped as a demi-god by the local inhabitants. It is curious, though, that no one at the time - nor Herodotus with the benefit of hindsight - seems to have detected any ill-omen in the death of this enormous Persian of royal blood at the very start of the campaign.
The Greeks through whose lands the king and his army were now passing found out what Alexander of Macedon had long ago anticipated - they were eaten out of house and home. It was not only the locust-like swarms of the troops and the beasts that denuded all the land around, but the senior citizens through whose townships Xerxes passed were compelled, as vassals of the king, to see that he was suitably entertained. Apart from all the food for Xerxes and his large personal retinue it was natural that they should set it all before their overlord in suitable vessels of gold and silver. To their dismay they found that, when the tent of Xerxes was struck in the morning, all the table-gear on which they had lavished so much money was moved off with it. It was a good thing, as one leading citizen remarked, that Xerxes did not dine twice a day, or they would all be totally ruined.
Following the stop at Acanthus the army and the fleet had necessarily to part. While the army made its way westward across to Therma at the head of the Thermaic Gulf, the fleet, after the passage of the canal was over, had to round the other two capes of Chalcidice before heading up north for the next rendezvous. It is possible that not even the excellent information system of the Persians had quite prepared the army for the difficulty of this part of the terrain. Something like a third of the troops had to go ahead and cut a way through the dense forest-land and it was the fleet which, possibly to the surprise of all concerned, reached Therma first. One wonders whether the warnings of Artabanus ever echoed in Xerxes’ ears. It was already late July, and here he was without even having started the campaign. July would burn into August and then with September, when the Mediterranean becomes unstable and often violently stormy, he would be far from home and well into the country of his enemies. If it had taken so long to get this far unopposed it is possible that his sleep may have been troubled by the thought of what might happen when both army and fleet were deep into a hostile sea and land.
Whatever his private feelings, or those of his advisers, may have been, the fact remains that it was necessary to make a fairly lengthy stay at this point on the route. He had to wait for last reports from his heralds, despatched long in advance, as to the dispositions of the Greek states and which of them, at this late hour, were prepared to surrender and which (he certainly knew of two) were determined to resist. Xerxes’ love of natural beauty, very typical of a Persian of his caste, has already been commented upon, and now from the head of the Gulf he could see in the clear early light of day the peaks of Mount Olympus and of Ossa shining to the south. The home of the Greek gods beckoned. Besides which, there was a good practical reason for his next action. He was ‘informed that between the two mountains there lay a narrow gorge through which ran the river Peneus, and also a road that led into Thessaly’. The king decided to go down by sea and inspect the river mouth for himself. ‘No sooner had the fancy taken him than he acted upon it. Going aboard the Sidonian vessel which he always used for any such occasion, he gave the signal for the rest of the fleet to put to sea, leaving the army behind in its encampments.’
Xerxes knew well enough from his advisers that, largely through the machinations of Alexander of Macedon, the Tempe pass had long been evacuated by the Greeks and was now free for the passage of troops. The route had its attractions for it passed straight between the mountains (thus obviating a long detour to the northwest of Olympus and Ossa). Xerxes would then have his army on the direct line south towards the head of the Malian Gulf where he must hope that his fleet, having worsted any Greek opposition at sea, would be waiting ready for the passage of the Euripus channel between Euboea and the mainland. What the Persians suffered from throughout the campaign - although they had had spies all over the place for years and although they had well-informed Greek advisers with them - was that salient thing, local knowledge. Since there were no maps or charts, local knowledge was of prime consequence in ancient wars: something which meant that the invader of foreign territory was always at a grave disadvantage. Even in the twentieth century, as has been found out in numerous theatres of war, the personal acquaintanceship with the terrain held only by native villagers gives a considerable ‘edge’ over any invader however numerous, efficient, and well armed.
It did not take Xerxes and his immediate staff long to see that the Tempe gorge would be useless - possibly disastrous - for the passage of a host so large as theirs. Its main attraction was obvious: it was less than five miles long, thus saving not only days of time but the exhaustion of troops and baggage train under the high-summer weather. Its principal disadvantage was immediately and equally obvious: it was too narrow. The broiling River Peneus, while it would provide them with all the water they could possibly need, took up so large a part of the pass that in a number of places there would not be more space than some fifty yards through which men and animals could pass. To take an army of tens of thousands through such a defile was to invite disaster. It was true, as Alexander had told them, that the hoplites had withdrawn, but they might return again. And could one trust Alexander, or even many of the supposedly friendly northern Greeks, not to take advantage of the Persian predicament if they were so foolish as to put their whole head, and then sinuous body, into such a trap designed by nature for the decimation of men? The answer was obvious. Xerxes admired the breathtaking view, ‘that deep romantic chasm which slanted down the green hill, but recognised it as ‘A savage place!’ There was nothing for it. They would have to take the long northern route round by the line of the Haliacmon river and strike inland behind Olympus, Ossa, and Pelion.
The gods of Greece lay in her formidable mountains, in her harsh and largely inhospitable terrain, and in the scouring northerly winds of the Aegean Sea.