History of the Peloponnesian War

While the Peloponnesians were yet sailing up, Demosthenes anticipated them by secretly sending two ships with a message to Eurymedon and the Athenians on board the fleet at Zacynthus to join him, as the place was in danger.

So the ships sailed with all speed, according to the orders of Demosthenes; while the Lacedaemonians prepared to assault the place both by land and sea, hoping easily to take a building completed in haste, and with only a few men in it.

At the same time, expecting the arrival of the Athenian fleet from Zacynthus to its relief, they intended, in case of their not having taken it before, to bar also the entrances into the harbour, that the Athenians might not be able to come to anchor in it.

For the island that is called Sphacteria both secures the harbour, by stretching in a line with it, and close off it, and narrows its entrances; on one side, near the Athenian fortifications and Pylus, leaving a passage for two ships; on the other, towards the rest of the mainland, for eight or nine. It was all woody and pathless from its desert condition, and in extent about fifteen stades. The entrances then they intended to bar with a close line of vessels, with their heads looking outwards;