History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
and yet they had been brought to such a pitch of determination as no one would have credited before it happened, if he had heard of it. That they, who were themselves being besieged by the Peloponnesians by means of a fortress in their country, should not even thus abandon Sicily, but should in turn be there besieging Syracuse in the same manner, a city which taken by itself is not smaller than the city of Athens; and that they should have caused the Hellenic world to make so amazing a miscalculation of their power and daring —inasmuch as at the beginning of the war some thought that they could hold out one year, others two years, others longer but never more than three years, if the Peloponnesians should invade their country—that in the seventeenth year after the first invasion of Attica they should have gone to Sicily, when already war-worn in all respects, and should have undertaken another war no whit less serious than that which was already being waged with the Peloponnesus—this, I say, was incredible.
For all these reasons, and because at that time Deceleia was doing them much injury and the general expenses which were accruing were very great, they became crippled in the matter of money; and it was at this time that they imposed upon their subjects, instead of a tribute, a duty of five per cent. on all commodities imported or exported by sea, thinking that in this way they should derive more revenue. For their expenses were not on the same scale as before, but had become far heavier, in proportion as the war had become greater, and their revenues were steadily failing.
As for the Thracians,[*](cf. xxvii. 1.) then, who had come too late for Demosthenes, the Athenians immediately sent them back, being unwilling on account of the present shortage of money to incur expense; and they commissioned Dieitrephes to conduct them, giving him instructions to use them, as he sailed along the coast (for they would go by way of the Euripus), in doing whatever damage he could to the enemy.
So he disembarked them in the territory of Tanagra and made a hasty raid; then he sailed immediately after nightfall from Chalcis in Euboea across the Euripus and landing the Thracians in Boeotian territory led them against Mycalessus.
During the night he bivouacked unobserved near the sanctuary of Hermes, about sixteen stadia distant from Mycalessus, but at daybreak assaulted the town, which was not large, and took it; for he fell upon the people off their guard and not expecting that anybody would ever march so far inland from the sea and attack them; furthermore, their wall was weak, and at some points had even fallen down, while elsewhere it had been built low, and at the same time the gates were open because of their feeling of security.