Diodorus of Sicily: Greek historian, author of the Library of World History. His activities can be dated between 60 and 30 BCE.
The greatest Athenian victory in the Archidamian War was, no doubt, the capture of Pylos in the southwest of the Peloponnese in 425 by general Demosthenes and his political ally Cleon. Here, the Athenians could receive runaway slaves and helots, which did great damage to the Spartan economy. Even better, a small Spartan army that had occupied the nearby island of Sphacteria surrendered: 292 Spartans, including 120 elite Spartiates, surrendered. From now on, the Spartans could no longer invade Attica, because the Athenians would in that case execute the POWs. Even more important was that the myth of Spartan invincibility had been shattered to pieces.
The story is told by several authors. The most important one is Thucydides (History of the Peloponnesian War 4.3-23, 26-40), but the great historian, who profoundly hated Cleon, presents this victory as a bit of good luck, whereas the operation appears to have been carefully planned. The account of Diodorus (Library of World History, 12.61-63) is, although it is much briefer, less biased. It is almost certainly based on Ephorus of Cyme.
The translation was made by C.H. Oldfather, with some modifications.
The Sphacteria Campaign
[12.61.1] Demosthenes now led an expedition against Pylos, intending to fortify this stronghold as a threat to the Peloponnese; for it is an exceptionally strong place, situated in Messenia and 75 kilometer distant from Sparta. Since he had at the time both many ships and an adequate number of soldiers, in twenty days he threw a wall about Pylos.
The Spartans, when they learned that Pylos had been fortified, gathered together a large force, both infantry and ships.
[12.61.2] Consequently, when they set sail for Pylos, they not only had a fleet of forty-five fully equipped triremes but also marched with an army of twelve thousand soldiers; for they considered it to be a disgraceful thing that men who were not brave enough to defend Attica while it was being ravagednote[A reference to the Athenian strategy until then. They had had allowed the Spartans to pillage their country and had concentrated all people in the city itself, which could easily be supplied from across the sea. As long as the "Long walls" connected the city to its port Piraeus, the city could never be captured.] should fortify and hold a fortress in the Peloponnese.
[12.61.3] Now these forces under the command of Thrasymedes pitched their camp in the neighborhood of Pylos. And since the troops were seized by an eager desire to undergo any and every danger and to take Pylos by storm, the Spartans stationed the ships with their prows facing the entrance to the harbor in order that they might use them for blocking the enemy's attempt to enter, and assaulting the walls with the infantry in successive waves and displaying all possible rivalry, they put up contests of amazing valor.
[12.61.4] Also to the island called Sphacteria, which extends lengthwise to the harbor and protects it from the winds, they transported the best troops of the Spartans and their allies. This they did in their desire to forestall the Athenians in getting control of the island before them, since its situation was especially advantageous to the prosecution of the siege.
[12.61.5] And though they were engaged every day in the fighting before the fortifications and were suffering wounds because of the superior height of the wall, they did not relax the violence of their fighting. As a consequence, many of them were slain and not a few were wounded as they pressed upon a position which had been fortified.
[12.61.6] The Athenians, who had secured beforehand a place which was also a natural stronghold and possessed large supplies of missiles and a great abundance of everything else they might need, kept defending their position with spirit; for they hoped that, if they were successful in their design, they could carry the whole war to the Peloponnese and ravage, bit by bit, the territory of the enemy.
[12.62.1] Both sides displayed unsurpassable energy in the siege, and as for the Spartans in their assaults upon the walls, while many others were objects of wonder for their deeds of valor, the greatest acclaim was won by Brasidas.
[12.62.2] For when the captains of the triremes lacked the courage to bring the ships to land because of the rugged nature of the shore, he, being himself the commander of a trireme, called out in a loud voice to the pilot, ordering him not to spare the vessel but to drive the trireme at full speed to the land; for it would be disgraceful, he cried, for Spartans to be unsparing of their lives as they fought for victory, and yet to spare their vessels and to endure the sight of Athenians holding the soil of Laconia.
[12.62.3] And finally he succeeded in forcing the pilot to drive the ship forward and, when the trireme struck the shore, Brasidas, taking his stand on the gangway, fought off from there the multitude of Athenians who converged upon him. And at the outset he slew many as they came at him, but after a while, as numerous missiles assailed him, he suffered many wounds on the front of his body.
[12.62.4] In the end he suffered much loss of blood from the wounds, and as he lost consciousness his arm extended over the side of the ship and his shield, slipping off and falling into the sea, came into the hands of the enemy.
[12.62.5] After this Brasidas, who had built up a heap of many corpses of the enemy, was himself carried off half-dead from the ship by his men, having surpassed to such a degree all other men in bravery that, whereas in the case of all other men those who lose their shields are punished with death, he for that very reason won for himself glory.
[12.62.6] Now the Spartans, although they kept making continuous assaults upon Pylos and had lost many soldiers, remained steadfast in the fierce struggles. And one may well be amazed at the strange perversity of Fortune and at the singular character of her ordering of what happened at Pylos.
[12.62.7] For the Athenians, defending themselves from a base on Laconian soil, were gaining the mastery over the Spartans, whereas the Spartans, regarding their own soil as the enemy's, were assaulting the enemy from the sea as then base; and, as it happened, those who were masters of the land in this case controlled the sea, and those who held first place on the sea were beating off an attack on land which they held.
[12.63.1] Since the siege dragged on and the Athenians, after their victory with their ships, were preventing the conveyance of food to the land, the soldiers caught on the islandnote[Spacteria.] were in danger of death from starvation.
[12.63.2] Consequently the Spartans, fearing for the men left on the island, sent an embassy to Athens to discuss the ending of the war. When no agreement was being reached, they asked for an exchange of men, the Athenians to get back an equal number of their soldiers now held prisoner; but not even to this would the Athenians agree. Whereupon the ambassadors spoke out frankly in Athens, that by their unwillingness to effect an exchange of prisoners the Athenians acknowledged that Spartans were better men than they.
[12.63.3] Meanwhile the Athenians wore down the bodily strength of the Spartans on Sphacteria through their lack of provisions and accepted their formal surrender. Of the men who gave themselves up one 120 were Spartiates and one 180note[Thucydides says 172.] were of their allies.
[12.63.4] These, then, were brought by Cleon the leader of the populace, since he held the office of general when this took place, in chains to Athens; and the people voted to keep them in custody in case the Spartans should be willing to end the war, but to slay all the captives if they should decide to continue it.
[12.63.5] After this they sent for select troops from the Messenians who had been settled in Naupactus, joined to them an adequate force from their other allies, and turned over to them the garrisoning of Pylos; for they believed that the Messenians, by reason of their hatred of the Spartans, would show the greatest zeal in harrying Laconia by forays, once they were operating from a strong position as their base.
Such were the events about Pylos in this year.