History of the Peloponnesian War

When, then, we had in many engagements defeated the Syracusans, against whom we were sent, and had built the walls in which we are now lying, Gylippus, the Lacedaemonian, came with an army from the Peloponnese and some of the cities in Sicily. And though in the first battle he was beaten by us, in the one fought the next day we were driven from the field by numerous cavalry and dart-men, and retired within our walls.

At present, therefore, we have ceased working at our line of circumvallation, in consequence of the enemy's numbers, and are lying still; (for we should not, indeed, be able to avail ourselves of all our force, since the guarding of our lines has exhausted a considerable part of our heavy-armed;) while they, on the other hand, have carried past us a single wall, so that it is no longer possible to invest them, unless one should assault this counter-work with a large force, and take it.