Themistocles sees to it that the Greeks fight at Artemisium:

But now, the Greeks who had at last come to Artemisium saw a multitude of ships launched at Aphetae and forces everywhere, and contrary to all expectation, the barbarian was shown to be in much different shape than they had supposed. They accordingly lost heart and began to deliberate about flight from Artemisium homewards into Hellas. [2] Then the Euboeans, noticing that they were making such plans, entreated Eurybiades to wait a little while, till they themselves had removed their children and households. When they could not prevail with him, they tried another way and gave Themistocles, the Athenian admiral, a bribe of thirty talents on the condition that the Greek fleet should remain there and fight, when they fought, to defend Euboea.

V. This was the way in which Themistocles made the Greeks stay where they were: he gave Eurybiades for his share five talents of that money, as though he were making the present of his own money. When Eurybiades had been won over in this way, none of the rest was inclined to resist save Adimantus, son of Ocytus, the Corinthian admiral, who said that he would not remain but sail away from Artemisium; to him Themistocles, adding an oath, said: [2] “No, you of all men will not desert us, for I will give you a greater gift than the king of the Medes would send you for deserting your allies.” With that he sent three talents of silver to Adimantus ship. [3] These two, then, were won over by gifts, the Euboeans got what they wanted, and Themistocles himself was the gainer. No one knew that he had kept the rest of the money, and those who had received a part of it supposed that it had been sent for that purpose by the Athenians.