Thucydides, History of the Peloponnesian War
Benjamin Jowett, Ed.

27. During the same summer there arrived at Athens thirteen hundred Thracian targeteers¹ of the Dian race, who carried dirks; they were to have sailed with Demosthenes to Sicily, but came too late, and the Athenians determined to send them back to their native country. [2] Each soldier was receiving a drachma² per day; and to use them against Decelea would have been too expensive. [3] For during this summer Decelea had been fortified by the whole Peloponnesian army, and³ was henceforward regularly occupied for the annoyance of the country by a succession of garrisons sent from the allied cities, whose incursions did immense harm to the Athenians: the destruction of property and life which ensued did as much as anything to ruin the city. [4] Hitherto the invasions had been brief and did not prevent them from getting something from the soil in the interval; but now the Peloponnesians were continually on the spot; and sometimes they were reinforced by additional troops, but always the regular garrison, who were compelled to find their own supplies, overran and despoiled the country. The Lacedaemonian king, Agis, was present in person, and devoted his whole energies to the war. The sufferings of the Athenians were terrible. [5] For they were dispossessed of their entire territory; more than twenty thousand slaves had deserted⁴, most of them workmen; all their sheep and cattle had perished, and now that the cavalry had to go out every day and make descents upon Decelea or keep guard all over the country, their horses were either wounded by the enemy, or lamed by the roughness of the ground and the incessant fatigue.