The north wind handled them very roughly, casting away very many of their ships. It is said that the number of ships destroyed was three hundred, and more than twenty thousand men; for as this sea which is about Athos is very full of sea monsters, some were seized by these and so perished, while others were dashed against the rocks; and some of them did not know how to swim and perished for that cause, others again by reason of cold. {127} The army fared little better, for it was attacked by some Thracian tribesmen, and though Mardonius forced them to submit to him, he suffered so much loss in the fighting, that as his fleet also had been almost entirely destroyed, he was obliged to depart back to Asia having gained no honour in this undertaking. Two years went by, and then another expedition was planned. Before it started, Darius sent messengers to Athens and Sparta and other Greek states demanding of them earth and water, the symbols of submission to the Great King. Some states agreed to the demand, either because they were struck dumb with terror at the mere thought that the Great King might invade their land, or because they thought that he was certain to conquer and that by submitting at once they would secure themselves and their land from destruction. Athens and Sparta, however, refused uncompromisingly. The messengers were thrown by the Athenians into a pit, and by the Spartans into a well, and told that if they wanted earth and water they could get them for themselves. On hearing what had happened to his messengers, Darius gave orders to the generals to set out at once for Greece, and to punish every state which had refused submission by enslaving all the inhabitants and bringing them bound to Susa. In particular, Athens and Eretria, for their other misdeeds, were to receive the severest treatment. So the expedition started. Remembering the disaster at Mount Athos, the fleet sailed this time across the Aegean, touching at Naxos, the first of the Ionian cities that had revolted, {128} and which now received its punishment by being burnt and its people enslaved. Then the Persians went on to Delos, where they offered sacrifices to Apollo, and from there they sailed to Eretria which they immediately attacked. The city held out for six days and then traitors within the walls opened the gates to the Persians who entered and took the city. They burnt it to the ground and carried off all the inhabitants into slavery. And so Eretria was punished for her share in daring to burn a city of the Great King.