Cleon at Sphacteria Overview The memorable Battle of Sphacteria (Pylos) of 425 bce resulted indirectly:  from Athenian involvement with Sicily and from a storm which forced a fleet bound for Sicily into the harbor at Pylos. Important background aspects of this battle are: the Athenian' first involvement in Sicily in 457 bce; the Athenian settlement of the Messenian helots in Naupactus in 456 bce; Demosthenes' campaign in Aetolia in summer 426 bce; Demosthenes' campaign in Amphilochia in winter 426/5 bce.   Important aftermaths of this battle are: the battle of Amphipolis in 422, in which Cleon was killed and as a result of which Thucydides was exiled; the peace of Nicias of 421, which brought the first phase of the Peloponnesian War to an end. = a Thucydidean "landmark" event Click on the image to bring up the "landmark."