History of the Peloponnesian War

When in most of our battles we had beaten the Syracusans, against whom we were sent, and had built the fortifications in which we now are, there came Gylippus, a Lacedaemonian, with an army collected from the Peloponnesus and from some of the cities in Sicily. In the first battle he was defeated by us, but on the next day, under pressure from their numerous cavalry and javelin-men, we drew back within our walls.

At the present time, then, we have discontinued our work of circumvallation on account of the superior numbers of the enemy and are keeping quiet; for we cannot use our whole army because the guarding of the walls has absorbed a part of our heavy-armed force. The enemy meanwhile have built a single wall past ours, so that it is no longer possible to invest them, unless one should assault this counter-wall with a large force and take it.