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.
Nevertheless at dawn they reached the sea, and taking the road called Elorine marched on, intending when they reached the river Cacyparis[*](Modern Cassibili.) to follow this stream up into the interior of the island; for they hoped that the Sicels, whom they had sent for, would meet them in that region.
But when they came to the river, there also they found a Syracusan guard blocking the way with a wall and a palisade. Forcing their way past them, they crossed the river and advanced again towards another river, the Erineus;[*](Modern Cavallata.) for their guides bade them take that route.
Meanwhile, when day came[*](Sixth day of the retreat.) and the Syracusans and their allies realized that the Athenians had gone away, most of them blamed Gylippus, saying that he purposely had let the Athenians get away; and pursuing them in hot haste, following the road which they could readily see that the enemy had taken, they overtook them about dinnertime.
And when they came up with the troops under Demosthenes, which were far in the rear and proceeding in a rather leisurely and disorderly fashion, due to the confusion into which they had fallen the night before, they fell upon them at once and began a battle; and since they were separated from the others the Syracusan cavalry found it easier to surround them and drive them together.
The division of Nicias was about fifty stadia ahead; for Nicias marched his men more rapidly, thinking that in the circumstances safety lay, not in standing firm and fighting of their own choice, but in retreating as rapidly as possible, fighting only as they were forced to do so.