Under the great mortality and pressure of sickness at Athens, their operations of war naturally languished; while the enemies also, though more active, had but little success. A fleet of one hundred triremes, with one thousand hoplites on board, was sent by the Lacedæmonians under Knêmus to attack Zakynthus, but accomplished nothing beyond devastation of the open parts of the island, and then returned home. And it was shortly after this, towards the month of September, that the Ambrakiots made an attack upon the Amphilochian town called Argos, situated on the southern coast of the gulf of Ambrakia: which town, as has been recounted in the preceding chapter, had been wrested from them two years before by the Athenians, under Phormio, and restored to the Amphilochians and Akarnanians. The Ambrakiots, as colonists and allies of Corinth, were at the same time animated by active enmity to the Athenian influence in Akarnania, and by desire to regain the lost town of Argos. Procuring aid from the Chaonians, and some other Epirotic tribes, they marched against Argos, and after laying waste the territory, endeavored to take the town by assault, but were repulsed, and obliged to retire.[314] This expedition appears to have impressed the Athenians with the necessity of a standing force to protect their interest in those parts; so that in the autumn Phormio was sent with a squadron of twenty triremes to occupy Naupaktus, now inhabited by the Messenians, as a permanent naval station, and to watch the entrance of the Corinthian gulf.[315] We shall find in the events of the succeeding year ample confirmation of this necessity. [314] Thucyd. ii, 68. [315] Thucyd. ii, 69. Though the Peloponnesians were too inferior in maritime force to undertake formal war at sea against Athens, their single privateers, especially the Megarian privateers from the harbor of Nisæa, were active in injuring her commerce,[316]—and not merely the commerce of Athens, but also that of other neutral Greeks, without scruple or discrimination. Several merchantmen and fishing-vessels, with a considerable number of prisoners, were thus captured.[317] Such prisoners as fell into the hands of the Lacedæmonians,—even neutral Greeks as well as Athenians,—were all put to death, and their bodies cast into clefts of the mountains. In regard to the neutrals, this capture was piratical, and the slaughter unwarrantably cruel, judged even by the received practice of the Greeks, deficient as that was on the score of humanity: but to dismiss these neutral prisoners, or to sell them as slaves, would have given publicity to a piratical capture and provoked the neutral towns, so that the prisoners were probably slain as the best way of getting rid of them and thus suppressing evidence.[318] [316] Thucyd. iii, 51.