Agis was not aware that the Argive generals had taken up a new position, and thinking that the confederates were still stationed on the hill, he gave up his scheme of diverting the water, and directed his march towards the place where he had first encamped. As they proceeded thus in marching order, and quite unprepared for any hostile movement, the Spartans suddenly found themselves face to face with the whole Argive army, drawn up in order of battle. For one instant it seemed as if a panic were about to spread through the Spartan ranks; then their wonderful discipline prevailed, and with all promptitude, but without flurry or confusion, the necessary orders were passed from the King to the commanders of divisions, from these again to the colonels, from the colonels to the captains, and from the captains down to the sergeants, [Footnote: I have thought it best to give the English titles, which of course have only a general correspondence with the Greek Polemarch, Lochagus, etc.] who in their turn had to see that the required movement was executed by the men under their command: for such was the regular gradation of authority and responsibility in the Spartan army. Thanks to this perfect organization, in a very few minutes every man was in his place and ready for battle.
On the left wing of the Spartan army were posted the Sciritae, hardy mountaineers from southern Arcadia; next to them stood the enfranchised Helots, who had served under Brasidas in Thrace, and others of the same race who had received the Spartan citizenship in reward for public service; then came the main body of the Spartans themselves, and after them the rest of the Arcadian allies; while the right wing was assigned by immemorial privilege to the Tegeans, with whom were a few picked Spartans. The cavalry, never a very strong part of the Spartan army, were posted on either flank.
On the other side the Mantineans held the place of honour on the right wing, because the engagement was fought in their territory; next in order were the Arcadian allies of Argos, and after them, more towards the centre, stood a picked troop of a thousand Argives, trained and equipped at the public expense; then followed the main body of the Argive troops, with the rest of their allies, the Athenians occupying the extreme left. As to the numbers engaged, nothing certain is known.
Some time was lost by the Argive army in delivering the customary harangues addressed by the generals of the several contingents to their men, and this enabled the Spartans to steady their ranks before the fighting began. They, on their side, men of war from their youth, had no need of set speeches to remind them of their duty; but pithy words of exhortation passed from man to man, and high and clear rose their national war-songs, thrilling them with the memories of their heroic past. Then the signal was given on both sides to charge, and the Argives and their allies rushed impetuously to the onset, while the Spartans advanced to meet them with even and deliberate pace, timed to the music of numerous pipers, who were stationed at regular intervals in their ranks.
The regular equipment of the Greek infantry soldier consisted, besides his helmet and body-armour, of shield and lance, and in advancing to battle he had always a tendency to diverge towards the right, from a natural wish to keep his shielded side towards the enemy. This divergence from the forward direction was begun by the man posted on the extreme right; his comrade on the left followed his example, and the deflection was continued along the whole line. The consequence was that when two armies came into action, the left wing on either side was greatly outflanked by the opponents' right; and the battle of Mantinea affords no exception to this rule, for not even Spartan discipline was able to counteract the overpowering instinct of self-preservation. Seeing that his left wing was on the point of being outflanked by the Mantineans, Agis signalled to the Sciritae and Brasideans to draw off in a lateral direction towards the left, in order to present an equal line to the right wing of the enemy. The order was executed, and to fill up the gap thus produced on the left of his own centre, Agis ordered the Spartan officers commanding on his right wing to bring up their men and occupy the vacant space. They, however, flatly refused to obey the order, and consequently the Sciritae and Brasideans were assailed in front and on both flanks by overwhelming numbers, and driven back with great loss to their camp.
So completely were the Spartans out-manoeuvred and worsted in tactics, through the blunders of their general, and the cowardice of his subordinates. But in this terrible crisis they showed what native valour, aided by life-long discipline, can do. Leaving a victorious enemy in their rear, they advanced without flinching against the opposing centre, where the main body of the Argives were posted, with the troops of Orneae and Cleonaea supporting them on the left. Then it was seen that neither the courage of the Spartans, nor the terror of their name, had diminished with the lapse of time; for when the confederate troops found themselves face to face with the renowned warrior of the Eurotas, they turned and fled, almost without striking a blow, and trampling their comrades under foot, in their haste to avoid the thrust of the Spartan lances. The Athenians on the left wing were now in great danger; for the charge of the troops of Agis had cut them off from the centre, and they were attacked on the other flank by the Tegeans and Spartans. They were saved from immediate destruction by the exertions of their own cavalry, and presently found themselves at liberty to retire from the field; for Agis, having completed the rout of the main body, called off his men, and went to the relief of his own left. The Mantineans and the Argive Thousand made no effort to retrieve the fortunes of the day, but gave way before the first onset of the Spartans, and joined the flight of their comrades. The Mantineans suffered severely in their retreat, but of the Argives only a few were slain.
Such was the battle of Mantinea, which completely restored the military fame of the Spartans, and blotted out the reproach of cowardice and sloth which for some years past had rested on their name.
VI
One incident remains to be recorded, before we proceed to the crowning catastrophe of our great historical drama. The Athenians, it should be observed, were still nominally at peace with Sparta, and if they had been wise they would have taken the opportunity of this respite from hostilities to recover Amphipolis, and consolidate their empire in Thrace. Instead of this, they looked around for fresh conquests, and fixed their eyes on the little island of Melos, belonging to the Cyclad group, which had been colonized in very early times from Sparta.
The Melians had not joined the Confederacy of Delos, and they might therefore be reproached for sharing the protection of Athens without making any return. Beyond this the Athenians had no ground of complaint against them, for they had taken no part in the Peloponnesian War, but had remained quietly at home, occupied with their own affairs. But Athens claimed the haughty title of mistress of the sea, and pretended to regard the neutrality of one insignificant island as an open defiance of her power. Ten years before an Athenian fleet had been sent under Nicias to reduce the refractory Melians to subjection; but the attempt was unsuccessful, and Nicias withdrew, after having ravaged the outlying districts. Being now more at leisure, the Athenians resolved, in the mere wantonness of power, that Melos should only be suffered to exist as a dependency of Athens, and thirty triremes sailed from the harbour of Peiraeus to carry out the arbitrary decree.