History of the Peloponnesian War

After this, when there was a favourable opportunity, he led them on again. Now Nicias and the Athenians thought that, even if the Syracusans were unwilling to begin fighting, they themselves could not possibly look idly on while the wall was being built past their own—for already the enemy's wall had all but passed the end of the Athenians' wall, and if it once got by, from then on it would be all one to them whether they fought and conquered in every battle or did not fight at all— accordingly they advanced against the Syracusans.

And Gylippus, leading forth his hoplites more outside the walls than before, closed with the enemy, having his cavalry and javelin-men posted on the flank of the Athenians, in the open space where the work on both walls ended.

And in the battle his cavalry attacked the left wing of the Athenians, which was opposed to them, and routed it; and in consequence of this the rest of the army also was beaten by the Syracusans and driven headlong within the fortifications.

And the following night they succeeded in building their wall beyond the works of the Athenians and in getting past, so that they themselves were no longer hampered by them, and had altogether deprived the Athenians, even if they should be victorious, of the possibility of ever investing them.