The movement of a large body of Persian troops towards Megara on the route to the Isthmus of Corinth led to consternation, and the usual division of opinion, among the Greeks assembled at Salamis. It is clear that the Persians made every effort to ensure that the whole operation should be as noisy and ostentatious as possible - something that would hardly be likely if they had intended a serious attack on the Isthmian line. This was an exercise to set the Greeks at odds with one another, and to divert them from their concordance to stand together at Salamis.
An unusual story in Herodotus seems unwittingly to confirm this. An Athenian exile named Dicaeus was out in the plain to the north of Eleusis along with the exiled Spartan king Demaratus at the time when the Persian troops had been ordered on the road that leads past Eleusis. The two men were most probably alone together so that they could talk freely and discuss their situation in the light of current circumstances. Herodotus specifically states that Dicaeus used to retell the story in later years and would tell any sceptics to consult Demaratus if they wanted confirmation of it. ‘They saw a cloud of dust, such as might have been raised by an army of thirty thousand men on the march, coming from the direction of Eleusis, and were wondering what troops they could be, when they suddenly heard the sound of voices. Dicaeus thought he recognised the Iacchus song, which is sung at the Dionysiac mysteries… .’ This is the first indication that we get in Herodotus of any date after the occupation of Athens; for the sacred rites at Eleusis were held at the time of the full moon of what is now the month of September. This puts the date on which Dicaeus fancied for the moment that he witnessed something to do with the Eleusinian mysteries taking place (he was possibly an initiate himself) at about the time of the full moon of 17 September. Demaratus, who, as a Spartan, knew little or nothing about the rites of Eleusis, is said to have asked his companion the reason for the noise. Dicaeus - realising that, in view of the devastated state of Attica, it could not be the normal annual procession - told him that the sound and the dust cloud could only have some mystic significance. Coming as it did from the direction of Eleusis, he concluded that it must necessarily betoken something of ill-omen towards these foreign invaders of the sacred soil. He came to the conclusion that the singing was of some divine nature (not the voices of distant troops, who were out of sight, singing in a foreign mode and tongue) and that it could only mean that some unearthly power was about to save the Athenians and their allies. Pointing to the dust cloud, which seemed to provide a strange omen on that autumn day, he said to Demaratus that the direction in which it moved would show where the Great King would be worsted - whether by land or by sea. The Spartan told him that when they got back among the Persians he had better keep his mouth shut or he would certainly lose his head. While Demaratus was speaking the dust cloud rose high in the air and drifted towards Salamis… .
The folly of Eurybiades, as the Peloponnesians saw it, in agreeing to the plan of this stateless Athenian Themistocles, immediately provoked another violent debate.
The smothered feeling broke out into open resentment, and another meeting was held. All the old ground was gone over again, one side urging that it was useless to stay and fight for a country which was already in enemy hands, and that the fleet should sail and risk an action in defence of the Peloponnese [just what Xerxes hoped], while the Athenians, Aeginetans, and Megarians still maintained that they should stay and fight at Salamis.
Themistocles acted promptly. He left the meeting and sent for an Asiatic Greek slave, Sicinnus, who had been the guardian of his children. It is interesting that Herodotus says ‘he slipped away’, but this seems somewhat dubious since the absence of the principal figure in the discussion could hardly have gone unremarked. It is more probable that, having made his position clear, he left the others to shout and wrangle (in a manner not uncommon among modern Greeks). His choice of Sicinnus is interesting for it reveals that trust in the devoted family slave to be found also in Greek tragedy, and going back as far as Eumaeus, the swineherd of Odysseus. As Herodotus tells the story, it would seem that this action of Themistocles was unpremeditated and done on the spur of the moment, but from the use that he made of Sicinnus one feels it was something which he had long conceived in the event of a breakdown in the Greek resolve to stay at Salamis. Furthermore, the fact that Sicinnus was ordered to take a small boat and cross over to the Persian lines under cover of darkness suggests that Themistocles must have had some supporters who agreed with him on this last desperate ploy. A man in a boat could hardly have got away unnoticed at that crisis in Greek affairs without some considerable authority being exercised over those on guard at the various landing-stages.
The message that Sicinnus was told to relay was, on the surface, simple enough. In fact, a number of modern scholars, thinking in terms of the complex twentieth century, have been unable to credit that the Great King could ever have believed it. (This is the mistake of hindsight and over-sophistication.) Since the versions given both by Herodotus and by Aeschylus, who fought in the battle, are so similar they seem more than worthy of credence. Herodotus writes:
… Sicinnus made his way to the Persian commanders and said: T am the bearer of a secret communication from the Athenian commander, who is a well-wisher to your king and hopes for a Persian victory. He has told me to report to you that the Greeks are afraid and are planning to slip away. Only prevent them from slipping through your fingers, and you have at this moment an opportunity of unparalleled success. They are at daggers drawn with each other, and will offer no opposition - on the contrary, you will see the pro-Persians amongst them fighting the rest.’
There can be no doubt that Sicinnus did not have an audience with the king, but with some senior officers - possibly no more than the trierarchs of one or more of the Persian triremes. It seems surprising that he was not detained for further questioning, but it is possible that he may never even have left his boat for, ‘his message delivered, Sicinnus lost no time in getting away’. One can hazard the guess that this message was delivered in the early hours of 19 September, and purported to be the conclusions of the Greeks’ last council of war from which Themistocles had recently withdrawn. Quite apart from the account given by Herodotus the story of Sicinnus is borne out by Aeschylus in his play The Persians. It seems also confirmed by the fact that, after the war was over, Themistocles freed his former slave and had him made a citizen of Thespiae at a time ‘when the Thespians were enrolling additional citizens, and made him a rich man’. Themistocles - despite his many virtues - was not noted for his generosity, so one may reasonably conclude that Sicinnus performed a service that was almost ‘beyond the call of duty’.
Xerxes, it would seem, swallowed the tale. On the surface this is almost impossible to believe: the king and his advisers had never previously shown themselves at all ingenuous about the duplicity and cunning nature of the Greeks. On the other hand, they cannot have been ignorant of the fact that there was deep dissension among the Greeks at Salamis (they hardly needed Queen Artemisia to remind them of that) and it must have been clear to all that Xerxes’ manoeuvre in sending an army corps to march blatantly along the coast road in the direction of Megara would bring the division among the Peloponnesians and the Athenians to a head. The message that now reached them from this slave sent by Themistocles seemed to confirm this. Green comments that ‘Xerxes’ experience during this campaign, not least in Phocis and Boeotia, might well have convinced him that any Greek state’s resentment against Persia ran a very poor second to the implacable hatred it reserved for its own neighbours: why should Athens be any exception to this rule?’ And then there was the example of the Arcadians who had come over to join the Persian army after the defeat of the Spartans at Thermopylae. If Greeks from remote Arcadia were willing to defect, was it not possible that even the Athenians, despite their deep hostility to Persia, had now - having seen their city and their shrines go up in flames - abandoned hope and decided to throw their hand in with the all-conquering monarch? Spies must have been rife in those days, and word may even have reached the king that Themistocles had already threatened to pull out the Athenian fleet and found a new colony in southern Italy. In conclusion one must take into account the nature of the Great King himself.
Xerxes had not yet achieved the kind of overwhelming triumph that his nature craved. Thermopylae had been a dearly bought victory and the price paid for it in Persian dead had necessitated a cover-up before the men from the fleet could be invited over to inspect the scene. Furthermore, what was the destruction of a handful of men in a little rocky pass? This was not the way major battles were fought in the East, where the monarch sat and surveyed the whole field from some suitable place and watched an enormous drama opening before his eyes - a drama of which he was the author, director and producer, and which he expected to conclude exactly as he had planned it. The capture of undefended Athens, even the assault on the Acropolis, had not provided the denouement that was called for by the years of preparations: by the massive works of bridging the Hellespont and turning Mount Athos into an island. The epic nature of the whole expedition required a grand finale and now it seemed that the opportunity presented itself.
Although Xerxes was hardly the Oriental hubristic tyrant that Greek writers depicted, yet certainly there was enough arrogance in his nature to wish for a climactic battle to round off the campaign. The Greeks, furthermore, had not taken the bait of his advanced ships - proof, perhaps, that they were afraid? If this was so, then the likelihood of their trying to slip away under cover of darkness seemed plausible. Quite apart from the fact that it was now the third week of September, and the weather might be expected to break at any moment, there were other practical reasons why Xerxes would have wished to conclude the Greek campaign as swiftly as possible. Admirably organised though it was, the Persian Empire was held together by the military might of the army, the ability of his generals, councillors and advisers, and the presence of the Great King himself. Ionia, despite - or perhaps because of - the absence of its ships and commanders, was restless; Egypt, where the influence of the priests was still strong, had not forgotten the harrowing of its religious practices, nor forgotten its harsh conquest; and the borders of empire were always being frayed by savage tribes. Furthermore, Xerxes must have known of the failure of ‘Operation Europe’ in the West. For, whether the battle of Himera took place in August or September, the news would certainly have reached the Persians that the great Carthaginian expedition against Sicily had ended in disaster. There was every reason for haste.