History of the Peloponnesian War

The Syracusians, though such were their success in the battle by sea, yet they won the fortification in Plemmyrium, and set up three trophies, for every wall one. One of the two walls last taken they demolished; but two they repaired and kept with a garrison.

At the taking of these walls, many men were slain and many taken alive; and their goods, which altogether was a great matter, were all taken. For the Athenians using these works for their storehouse, there was in them much wealth and victual belonging unto merchants and much unto captains of galleys. For there were sails within it for forty galleys, besides other furniture, and three galleys drawn to land.

And this loss of Plemmyrium was it that most and principally impaired the Athenians' army. For the entrance of their provision was now no longer safe; for the Syracusians lying against them there with their galleys kept them out, and nothing could be brought in unto them but by fight; and the army besides was thereby otherwise terrified and dejected.