Several of the allies of Sparta were dissatisfied with the peace which she had concluded; and soon afterwards some of them determined to revive the ancient pretensions of Argos, and to make her the head of a new confederacy, which should include all Greece, with the exception of Sparta and Athens. The movement was begun by the Corinthians, and the league was soon joined by the Eleans, the Mantineans, and the Chalcidians.

Between Sparta and Athens themselves matters were far from being on a satisfactory footing. Sparta confessed her inability to compel the Boeotians and Corinthians to accede to the peace, or even to restore the town of Amphipolis. Athens consequently refused to evacuate Pylus, though she removed the Helots and Messenians from it. In the negotiations which ensued respecting the surrender of Pylus, Alcibiades took a prominent part. This extraordinary man had already obtained immense influence at Athens. Young, rich, handsome, profligate, and clever, Alcibiades was the very model of an Athenian man of fashion. In lineage he was a striking contrast to the plebeian orators of the day. He traced his paternal descent from Ajax, whilst on his mother's side he claimed relationship with the Alcmaeonidae and consequently with Pericles. On the death of his father Clinias Pericles had become his guardian. From early youth the conduct of Alcibiades was marked by violence, recklessness, and vanity. He delighted in astonishing the more sober portion of the citizens by his capricious and extravagant feats. He was utterly destitute of morality, whether public or private. But his vices were partly redeemed by some brilliant qualities. He possessed both boldness of design and vigour of action; and, though scarcely more than thirty at the time of which we are now speaking, he had already on several occasions distinguished himself by his bravery. His more serious studies were made subservient to the purposes of his ambition, for which some skill as an orator was necessary. In order to attain it he frequented the schools of the sophists, and exercised himself in the dialectics of Prodicus, Protagoras, and above all of Socrates.

Such was the man who now opposed the application of the Lacedaemonian ambassadors. Their reception had been so favourable, that Alcibiades alarmed at the prospect of their success, resorted to a trick in order to defeat it. He called upon the Lacedaemonian envoys, one of whom happened to be his personal friend; and he advised them not to tell the Assembly that they were furnished with full powers, as in that case the people would bully them into extravagant concessions, but rather to say that they were merely come to discuss and report. He promised, if they did so, to speak in their favour, and induce the Assembly to grant the restitution of Pylus, to which he himself had hitherto been the chief obstacle. Accordingly on the next day, when the ambassadors were introduced into the Assembly, Alcibiades, assuming his blandest tone and most winning smile, asked them on what footing they came and what were their powers. In reply to these questions, the ambassadors, who only a day or two before had told Nicias and the Senate that they were come as plenipotentiaries, now publicly declared, in the face of the Assembly, that they were not authorized to conclude, but only to negotiate and discuss. At this announcement, those who had heard their previous declaration could scarcely believe their ears. A universal burst of indignation broke forth at this exhibition of Spartan duplicity; whilst, to wind up the scene, Alcibiades, affecting to be more surprised than any, distinguished himself by being the loudest and bitterest in his invectives against the perfidy of the Lacedaemonians.

Shortly afterwards Alcibiades procured the completion of a treaty of alliance for 100 years with Argos, Elis, and Mantinea (B.C. 420). Thus were the Grecian states involved in a complicity of separate and often apparently opposite alliances. It was evident that allies so heterogeneous could not long hold together; nevertheless, nominally at least, peace was at first observed.

In the July which followed the treaty with Argos, the Olympic games, which recurred every fourth year, were to be celebrated. The Athenians had been shut out by the war from the two previous celebrations; and curiosity was excited throughout Greece to see what figure Athens would make at this great Pan-Hellenic festival. War, it was surmised, must have exhausted her resources, and would thus prevent her from appearing with becoming splendour. But from this reproach she was rescued by the wealth and vanity, if not by the patriotism, of Alcibiades. By his care, the Athenian deputies exhibited the richest display of golden ewers, censers, and other plate to be used in the public sacrifice and procession; whilst for the games he entered in his own name no fewer than the unheard-of number of seven four-horsed chariots, of which one gained the first, and another the second prize. Alcibiades was consequently twice crowned with the olive, and twice proclaimed victor by the herald.

The growing ambition and success of Alcibiades prompted him to carry his schemes against Sparta into the very heart of Peloponnesus, without, however, openly violating the peace.

The Lacedaemonians now found it necessary to act with more vigour; and accordingly in B.C. 418 they assembled a very large army, under the command of the Spartan king, Agis. A decisive battle was fought near Mantinea, in which Agis gained a brilliant victory over the Argives and their allies. This battle and that of Delium were the two most important engagements that had yet been fought in the Peloponnesian war. Although the Athenians had fought on the side of the Argives at Mantinea, the peace between Sparta and Athens continued to be nominally observed.

In B.C. 416 the Athenians attacked and conquered Melos, which island and Thera were the only islands in the AEgean not subject to the Athenian supremacy. The Melians having rejected all the Athenian overtures for a voluntary submission, their capital was blockaded by sea and land, and after a siege of some months surrendered. On the proposal, as it appears, of Alcibiades, all the adult males were put to death, the women and children sold into slavery, and the island colonized afresh by 500 Athenians. This horrible proceeding was the more indefensible, as the Athenians, having attacked the Melians in full peace, could not pretend that they were justified by the custom of war in slaying the prisoners. It was the crowning act of insolence and cruelty displayed during their empire, which from this period began rapidly to decline.

The event destined to produce that catastrophe - the intervention of the Athenians in the affairs of Sicily - was already in progress. A quarrel had broken out between Egesta and Selinus, both which cities were seated near the western extremity of Sicily; and Selinus, having obtained the aid of Syracuse, was pressing very hard upon the Egestaeans. The latter appealed to the interests of the Athenians rather than to their sympathies. They represented how great a blow it would be to Athens if the Dorians became predominant in Sicily, and joined the Peloponnesian confederacy; and they undertook, if the Athenians would send an armament to their assistance, to provide the necessary funds for the prosecution of the war. Their most powerful advocate was Alcibiades, whose ambitious views are said to have extended even to the conquest of Carthage. The quieter and more prudent Nicias and his party threw their weight into the opposite scale. But the Athenian assembly, dazzled by the idea of so splendid an enterprise, decided on despatching a large fleet under Nicias, Alcibiades, and Lamachus, with the design of assisting Egesta, and of establishing the influence of Athens throughout Sicily, by whatever means might be found practicable.

For the next three months the preparations for the undertaking were pressed on with the greatest ardour. Young and old, rich and poor, all vied with one another to obtain a share in the expedition. Five years of comparative peace had accumulated a fresh supply both of men and money; and the merchants of Athens embarked in the enterprise as in a trading expedition. It was only a few of the wisest heads that escaped the general fever of excitement, The expedition was on the point of sailing, when a sudden and mysterious event converted all these exulting feelings into gloomy foreboding.

At every door in Athens, at the corners of streets, in the market place, before temples, gymnasia, and other public places, stood Hermae, or statues of the god Hermes, consisting of a bust of that deity surmounting a quadrangular pillar of marble about the height of the human figure. When the Athenians rose one morning towards the end of May, 415 B.C., it was found that all these figures had been mutilated during the night, and reduced by unknown hands to a shapeless mass. The act inspired political, as well as religious, alarm. It seemed to indicate a widespread conspiracy, for so sudden and general a mutilation must have been the work of many hands. The sacrilege might only be a preliminary attempt of some powerful citizen to seize the despotisn, and suspicion pointed its finger at Alcibiades. Active measures were taken and large rewards offered for the discovery of the perpetrators. A public board was appointed to examine witnesses, which did not, indeed, succeed in eliciting any facts bearing on the actual subject of inquiry, but which obtained evidence respecting similar acts of impiety committed at previous times in drunken frolics. In these Alcibiades himself was implicated; and though the fleet was on the very eve of departure, a citizen rose in the assembly and accused Alcibiades of having profaned the Eleusinian mysteries by giving a representation of them in a private house, producing in evidence the testimony of a slave. Alcibiades denied the accusation, and implored the people to have it investigated at once. His enemies, however, had sufficient influence to get the inquiry postponed till his return; thus keeping the charge hanging over his head, and gaining time to poison the public mind against him.

The Athenian fleet, consisting of 100 triremes, and having on board 1500 chosen Athenian hoplites, as well as auxiliaries, at length set sail, and proceeded to Corcyra, where it was joined by the other allies in the month of July, 415 B.C. Upon arriving at Rhegium the generals received the discouraging news that Egesta was unable to contribute more than thirty talents. A council of war was now held; and it was finally resolved to gain as many allies as they could among the Greek cities in Sicily, and, having thus ascertained what assistance they could rely upon, to attack Syracuse and Selinus.

Naxos joined the Athenians, and shortly afterwards they obtained possession by surprise of the important city of Catana, which was now made the head-quarters of the armament. Here an unwelcome message greeted Alcibiades. after his departure from Athens, Thessalus, the son of Cimon, preferred an indictment against him in consequence of his profanation of the Eleusinian mysteries. The Salaminian, or state, trireme was despatched to Sicily, carrying the decree of the assembly for Alcibiades to come home and take his trial. The commander of the Salaminia was, however, instructed not to seize his person, but to allow him to sail in his own trireme. Alcibiades availed himself of this privilege to effect his escape. When the ships arrived at Thurii in Italy, he absconded, and contrived to elude the search that was made after him, Nevertheless, though absent, he was arraigned at Athens, and condemned to death; his property was confiscated; and the Eumolpidae, who presided ever the celebration of the Eleusinian mysteries, pronounced upon him the curses of the gods. On hearing of his sentence Alcibiades is said to have exclaimed, "I will show them that I am still alive."

Three months had now been frittered away in Sicily, during which the Athenians had done little or nothing, if we except the acquisition of Naxos and Catana. Nicias now resolved to make an attempt upon Syracuse. By a false message that the Catanaeans were ready to assist in expelling the Athenians, he induced the Syracusans to proceed thither in great force, and he availed himself of their absence to sail with his whole fleet into the Great Harbour of Syracuse, where he landed near the mouth of the Anapus. The Syracusans, when they found that they had been deceived at Catana, marched back and offered Nicias battle in his new position. The latter accepted it, and gained the victory; after which he retired to Catana, and subsequently to Naxos into winter quarters.

The Syracusans employed the winter in preparations for defence. They also despatched envoys to Corinth and Sparta to solicit assistance, in the latter of which towns they found an unexpected advocate. Alcibiades, having crossed from Thurii to Cyllene in Peloponnesus, received a special invitation to proceed to Sparta. Here he revealed all the plans of Athens, and exhorted the Lacedaemonians to frustrate them. For this purpose he advised them to send an army into Sicily, under the command of a Spartan general, and, by way of causing a diversion, to establish a fortified post at Decelea in the Attic territory. The Spartans fell in with these views, and resolved to send a force to the assistance of Syracuse in the spring, under the command of Gylippus.

Nicias, having received reinforcements from Athens, recommenced hostilities as soon as the season allowed of it, and resolved on besieging Syracuse. That town consisted of two parts - the inner and the outer city. The former of these - the original settlement was comprised in the island of Ortygia; the latter afterwards known by the name of Achradina, covered the high ground of the peninsula north of Ortygia, and was completely separate from the inner city. The island of Ortygia, to which the modern city is now confined, is of an oblong shape, about two miles in circumference, lying between the Great Harbour on the west, and the Little Harbour on the east, and separated from the mainland by a narrow channel. The Great Harbour is a splendid bay, about five miles in circumference, and the Little Harbour was spacious enough to receive a large fleet of ships of war. The outer city was surrounded on the north and east by the sea and by sea-walls which rendered an assault on that side almost impracticable. On the land side it was defended by a wall, and partly also by the nature of the ground, which in some part was very steep. West and north-west of the wall of the outer city stood two unfortified suburbs, which were at a later time included within the walls of Syracuse under the names of Tyche and Neapolis. Between these two suburbs the ground rose in a gentle acclivity to the summit of the ranges of hills called Epipolae.

It was from the high ground of Epipolae that Syracuse was most exposed to attack. Nicias landed at Leon, a place upon the bay of Thapsus, at the distance of only six or seven stadia from Epipolae, took possession of Epipolae, and erected on the summit a fort called Labdalum. Then coming farther down the hill towards Syracuse, he built another fort of a circular form and of considerable size at a place called Syke. From the latter point he commenced his line of circumvallation, one wall extending southwards from Syke to the Great Harbour, and the other wall running northwards to the outer sea. The Athenians succeeded in completing the circumvallation towards the south, but in one of their many engagements with the Syracusans they lost the gallant Lamachus. At the same time, the Athenian fleet entered the Great Harbour, where it was henceforth permanently established. The northern wall was never completed, and through the passage thus left open the besieged continued to obtain provisions. Nicias, who, by the death of Lamachus, had become sole commander, seemed now on the point of succeeding. The Syracusans were so sensible of their inferiority in the field that they no longer ventured to show themselves outside the walls. They began to contemplate surrender, and even sent messages to Nicias to treat of the terms. This caused the Athenian commander to indulge in a false confidence of success, and consequent apathy; and the army having lost the active and energetic Lamachus, operations were no longer carried on with the requisite activity.

It was in this state of affairs that the Spartan commander, Gylippus, passed over into Italy with a little squadron of four ships, with the view merely of preserving the Greek cities in that country, supposing that Syracuse, and, with her, the other Greek cities in Sicily, were irretrievably lost. At Tarentum he learned to his great surprise and satisfaction that the Athenian wall of circumvallation at Syracuse had not yet been completed on the northern side. He now sailed through the straits of Messana, which were left completely unguarded, and arrived safely at Himera on the north coast of Sicily. Here he announced himself as the forerunner of larger succours, and began to levy an army which the magic of the Spartan name soon enabled him to effect; and in a few days he was in a condition to march towards Syracuse with about 3000 men. The Syracusans now dismissed all thoughts of surrender, and went out boldly to meet Gylippus, who marched into Syracuse over the heights of Epipolae, which the supineness of Nicias had left unguarded. Upon arriving in the city, Gylippus sent a message to the Athenians allowing them a five days' truce to collect their effects and evacuate the island. Nicias returned no answer to this insulting proposal; but the operations of Gylippus soon showed that the tide of affairs was really turned. His first exploit was to capture the Athenian fort at Labdalum, which made him master of Epipolae. He next commenced constructing a counter-wall to intersect the Athenian lines on the northern side. This turn of affairs induced those Sicilian cities which had hitherto hesitated to embrace the side of Syracuse. Gylippus was also reinforced by the arrival of thirty triremes from Corinth, Leucas, and Ambracia. Nicias now felt that the attempt to blockade Syracuse with his present force was hopeless. He therefore resolved to occupy the headland of Plemmyrium, the southernmost point of the entrance to the Great Harbour, which would be a convenient station for watching the enemy, as well as for facilitating the introduction of supplies. Here he accordingly erected three forts and formed a naval station. Some slight affairs occurred in which the balance of advantage was in favour of the Syracusans. By their change of station the Athenians were now a besieged rather than a besieging force. Their triremes were becoming leaky, and their soldiers and sailors were constantly deserting. Nicias himself had fallen into a bad state of health; and in this discouraging posture of affairs he wrote to Athens requesting to he recalled, and insisting strongly on the necessity of sending reinforcements.

The Athenians refused to recall Nicias, but they determined on sending a large reinforcement to Sicily, under the joint command of Demosthenes and Eurymedon. The news of these fresh and extensive preparations incited the Lacedaemonians to more vigorous action. The peace, if such it can be called, was now openly broken; and in the spring of 413 B.C. the Lacedaemonians, under King Agis, invaded Attica itself, and, following the advice of Alcibiades, established themselves permanently at Decelia, a place situated on the ridge of Mount Parnes about 14 miles north of Athens, and commanding the Athenian plain. The city was thus placed in a state of siege. Scarcity began to be felt within the walls; the revenues were falling off, whilst on the other hand expenses were increasing.

Meanwhile in Sicily the Syracusans had gained such confidence that they even ventured on a naval engagement with the Athenians. In the first battle the Athenians were victorious, but the second battle, which lasted two days, ended in their defeat. They were now obliged to haul up their ships in the innermost part of the Great Harbour, under the lines of their fortified camp. A still more serious disaster than the loss of the battle was the loss of their naval reputation. It was evident that the Athenians had ceased to be invincible on the sea; and the Syracusans no longer despaired of overcoming them on their own element.

Such was the state of affairs when, to the astonishment of the Syracusans, a fresh Athenian fleet of 75 triremes, under Demosthenes and Eurymedon, entered the Great Harbour with all the pomp and circumstance of war. It had on board a force of 5000 hoplites, of whom about a quarter were Athenians, and a great number of light-armed troops. The active and enterprising character of Demosthenes led him to adopt more vigorous measures than those which had been hitherto pursued. He saw at once that whilst Epipolae remained in the possession of the Syracusans there was no hope of taking their city, and he therefore directed all his efforts to the recapture of that position. But his attempts were unavailing. He was defeated not only in an open assault upon the Syracusan wall, but in a nocturnal attempt to carry it by surprise. These reverses were aggravated by the breaking out of sickness among the troops. Demosthenes now proposed to return home and assist in expelling the Lacedaemonians from Attica, instead of pursuing an enterprise which seemed to be hopeless. But Nicias, who feared to return to Athens with the stigma of failure, refused to give his consent to this step. Demosthenes then urged Nicias at least to sail immediately out of the Great Harbour, and take up their position either at Thapsus or Catana, where they could obtain abundant supplies of provisions, and would have an open sea for the manoeuvres of their fleet. But even to this proposal Nicias would not consent; and the army and navy remained in their former position. Soon afterwards, however, Gylippus received such large reinforcements, that Nicias found it necessary to adopt the advice of his colleague. Preparations were secretly made for their departure, the enemy appear to have had no suspicion of their intention and they were on the point of quitting their ill- fated quarters on the following morning, when on the very night before (27 Aug. 413 B.C.) an eclipse of the moon took place. The soothsayers who were consulted said that the army must wait thrice nine days, a full circle of the moon, before it could quit its present position; and the devout and superstitious Nicias forthwith resolved to abide by this decision.

Meanwhile the intention of the Athenians became known to the Syracusans, who determined to strike a blow before their enemy escaped. They accordingly attacked the Athenian station both by sea and land. On land the attack of Gylippus was repulsed; but at sea the Athenian fleet was completely defeated, and Eurymedon, who commanded the right division, was slain The spirits of the Symcusans rose with their victories; and though they would formerly have been content with the mere retreat of the Athenians, they now resolved on effecting their utter destruction. With this view they blocked up the entrance of the Great Harbour with a line of vessels moored across it. All hope seemed now to be cut off from the Athenians, unless they could succeed in forcing this line and thus effecting their escape. The Athenian fleet still numbered 110 triremes, which Nicias furnished with grappling-irons, in order to bring the enemy to close quarters, and then caused a large proportion of his land- force to embark.

Never perhaps was a battle fought under circumstances of such intense interest, or witnessed by so many spectators vitally concerned in the result. The basin of the Great Harbour, about 5 miles in circumference, in which nearly 200 ships, each with crews of more than 200 men, were about to engage, was lined with spectators. The Syracusan fleet was the first to leave the shore. A considerable portion was detached to guard the barrier at the mouth of the harbour. Hither the first and most impetuous attack of the Athenians was directed, who sought to break through the narrow opening which had been left for the passage of merchant vessels. Their onset was repulsed, and the battle then became general. The shouts of the combatants, and the crash of the iron heads of the vessels as they were driven together, resounded over the water, and were answered on shore by the cheers or wailings of the spectators as their friends were victorious or vanquished. For a long time the battle was maintained with heroic courage and dubious result. At length, as the Athenian vessels began to yield and make back towards the shore, a universal shriek of horror and despair arose from the Athenian army, whilst shouts of joy and victory were raised from the pursuing vessels, and were echoed back from the Syracusans on land. As the Athenian vessels neared the shore their crews leaped out, and made for the camp, whilst the boldest of the land army rushed forward to protect the ships from being seized by the enemy. The Athenians succeeded in saving only 60 ships, or about half their fleet. The Syracusan fleet, however, had been reduced to 50 ships; and on the same afternoon, Nicias and Demosthenes, as a last hope of escape, exhorted their men to make another attempt to break the enemy's line, and force their way out of the harbour. But the courage of the crews was so completely damped that they positively refused to re-embark.

The Athenian army still numbered 40,000 men; and as all chance of escape by sea was now hopeless, it was resolved to retreat by land to some friendly city, and there defend themselves against the attacks of the Syracusans. As the soldiers turned to quit that fatal encampment, the sense of their own woes was for a moment suspended by the sight of their unburied comrades, who seemed to reproach them with the neglect of a sacred duty; but still more by the wailings and entreaties of the wounded, who clung around their knees, and implored not to be abandoned to certain destruction. Amid this scene of universal woe and dejection, a fresh and unwonted spirit of energy and heroism seemed to be infused into Nicias. Though suffering under an incurable complaint, he was everywhere seen marshalling his troops and encouraging them by his exhortations. The march was directed towards the territory of the Sicels in the interior of the island. The army was formed into a hollow square with the baggage in the middle; Nicias leading the van, and Demosthenes bringing up the rear. The road ascended by a sort of ravine over a steep hill called the Acraean cliff on which the Syracusans had fortified themselves. After spending two days in vain attempts to force this position, Nicias and Demosthenes resolved during the night to strike off to the left towards the sea. But they were overtaken, surrounded by superior forces, and compelled to surrender at discretion. Out of the 40,000 who started from the camp only 10,000 at the utmost were left at the end of the sixth day's march, the rest had either deserted or been slain. The prisoners were sent to work in the stone-quarries of Achradina and Epipolae. Here they were crowded together without any shelter, and with scarcely provisions enough to sustain life. The numerous bodies of those who died were left to putrify where they had fallen, till at length the place became such an intolerable centre of stench and infection that, at the end of seventy days, the Syracusans, for their own comfort and safety, were obliged to remove the survivors, who were sold as slaves. Nicias and Demosthenes were condemned to death in spite of all the efforts of Gylippus and Hermocrates to save them.

Such was the end of two of the largest and best appointed armaments that had ever gone forth from Athens. Nicias, as we have seen, was from the first opposed to the expedition in which they were employed, as pregnant with the most dangerous consequences to Athens; and, though it must be admitted that in this respect his views were sound, it cannot at the same time be concealed that his own want of energy, and his incompetence as a general, were the chief causes of the failure of the undertaking. His mistakes involved the fall of Demosthenes, an officer of far greater resolution and ability than himself, and who, had his counsels been followed, would in all probability have conducted the enterprise to a safe termination, though there was no longer room to hope for success.