Both positions were liable to be turned. The danger at Artemisium was even greater than at. Thermopylę, for there was nothing to prevent the Persian fleet from sailing down the east coast of Euboea. Indeed we shall see that this was done, though, as it turned out, without any ill result to the Greeks. It is clear that the officers in command of the fleet were quite as uneasy as some of the army leaders at Thermopylę, nor was there any one who could exercise the control that Leonidas, in virtue of his commanding personality and his rank as a Spartan king, exercised over the allies.

An event of no great importance turned this uneasiness into panic. Two out of three ships which had been detached to keep a look out were captured by an advanced Persian squadron of ten ships. In consequence of this disaster, the fleet hastily retreated some fifty miles to the south to a spot where the channel between the mainland and Euboea is at its narrowest. It would probably have gone still further south but for the heavy loss which the Persian fleet suffered during a four days' storm. No less than four hundred ships were destroyed, and with them an uncounted multitude of men. The Greeks were so encouraged by the loss which had befallen the enemy, that they returned in all haste and took up their former station. Hence the battle of Artemisium.

The first incident was a Greek success. The Persian fleet took up its position in the great natural harbour which is now known as the Gulf of Volo. Fifteen ships belonging to it lagged so far behind the rest, that by the time they reached the south-eastern point of the gulf the main body had rounded it and were out of sight. But the Greek fleet was full in view; they mistook it for their own, sailed straight towards it, and were captured without a struggle. Notwithstanding this stroke of good fortune the Greek captains were full of fears. Even after the losses caused by the storm, the Persian fleet greatly outnumbered their own. They had two hundred and eighty ships, reckoning nine fifty-oars with the larger triremes or "three-bankers"; the Persians must have had more than twice as many.

The question of retreat again came up, and seemed very likely to be decided in the affirmative. A different result was brought about by a proceeding curiously characteristic of Greek ways of acting and thinking. The people of Euboea were in despair at the prospect of being deserted. It would be something, they thought, if they could secure a few days' grace in which to remove their portable property to a place of safety. They went to Eurybiades, the Spartan admiral, who was in supreme command, and begged him to postpone his departure for a short time. He refused the request. It would not, he said, be for the public interest. Then they went to Themistocles, the Athenian admiral. He was not the commander-in-chief, but he commanded the most numerous contingent, one hundred and twenty-seven ships, only thirteen short of the half. They offered him a splendid bribe of thirty talents (about £7,000 of our money) if he could procure for them the desired delay. Themistocles seems to have known the price of the men whom he had to buy. To Eurybiades he gave five talents, and the Spartan, to whom this sum probably seemed a fortune, changed his views about the public safety. The Corinthian commander, who had the most powerful squadron after that of Athens, had also to be bought. Themistocles dealt with him in the frankest way. "I will give you," he said, "more for staying than the Persians will give you for going." The Corinthian does not seem to have resented the suggestion that he was ready to be bribed by the enemies of his country, and accepted the two talents which Themistocles sent on board his ship. The Athenian kept the handsome balance in his own hands. We cannot say anything more for him than that he comes out of the transaction better than his colleagues. They believed that the better and safer course was to retreat. He, on the contrary, was convinced that the right policy was to stop and fight. But he never forgot his personal interests. In this case he made them harmonise; on other occasions his action was more doubtful. There is reason to think that, before the end of his career, he postponed the public good to his own.

The Persians, when they saw that the Greek fleet was still at Artemisium, had, it would seem, no thought but of how they might make sure of capturing the whole. They sent a squadron of two hundred ships to sail down the eastern coast of Euboea. These were to take the Greek in the rear, the main body waiting till the arrival of the squadron had been signalled. Meanwhile the Greeks had received some encouraging intelligence. A Greek diver, named Scyllias, who had been in the employ of the Persians, deserted to them.

He described the damage that had been done by the storm, and also informed them about the squadron that had been sent round Euboea. The first thought of the Greek admirals was to sail south, and meet this squadron. But on reflection, bolder counsels prevailed. Late in the afternoon they left their station, and sailed towards the hostile fleet. The Persians viewed the movement with astonishment, and the Asiatic Greeks with dismay, for though serving with the enemy, they wished well to their countrymen. The Greek ships were inferior, not only in numbers, but also in equipment, and they seemed to be rushing on destruction.

The Greeks began by assuming what seemed like a defensive position, forming a circle, with the sterns of their ships in close order, and the prows turned to the enemy. The enemy advanced to close with them, and then, at a concerted signal, the Greeks dashed at their opponents with such success that they captured thirty of their ships, the first prize falling, as indeed was fitting, to an Athenian ship. The Persians, recovered from the first surprise, began to hold their own better, and when night fell, the issue of the conflict was still doubtful. The captain of a ship from the island of Lemnos had the sagacity to see how the struggle would end, and deserted to the Greeks, receiving afterwards a handsome reward for his timely patriotism.

Again the "stars fought in their courses for Greece." That night there was a thunderstorm, with heavy rain and wind. The main body of the fleet did not suffer much material damage, but the crews were dismayed to see fragments of wrecks and bodies of the dead drifted in by the wind. These were, indeed, the tokens of a great disaster. The squadron that was sent round Euboea had been driven on a lee shore and absolutely destroyed. On the morrow the Persians made no movement, but the Greeks repeated the tactics of the day before. The news of the disaster to the Persian squadron had reached them, and they had been joined by a reinforcement of Athenian ships. This gave them new courage besides increasing their strength. Before the close of the day they captured some Cilician ships.

On the third day the Persian commanders, made desperate by failure, for they served a master who exacted a cruel penalty for ill-success, moved forward to engage the enemy, the Greeks awaiting their attack. The order of the Persian attack was in the shape of a half-moon, and its object to outflank the enemy on either side. The Greeks accepted the challenge. The result was not decisive. The Greeks sunk and captured more ships than they themselves lost. But their own loss was serious. Of the Athenian fleet especially, more than half was so injured as to require repair. By this time, too, the position had ceased to have any strategic value. The pass of Thermopylę had been forced by the Persians, and it was useless, therefore, to hold Artemisium. That night the Greek fleet retired southwards. Themistocles, before he went, caused to be engraved on a prominent rock an inscription which invited the Asiatic Greeks serving with the Persians to make common cause with their countrymen. "If these words," he reasoned with himself, "escape the knowledge of the king, they may bring these Greeks over to us; if they come to his knowledge, they will make him distrust them."