In pursuance of the treaty, the Lacedaemonians withdrew their harmosts and garrisons, whilst the Athenians recalled their fleet from the Ionian sea. Only one feeling prevailed at Sparta - a desire to crush Thebes. This city was regarded as doomed to destruction; and it was not for a moment imagined that, single- handed, she would he able to resist the might of Sparta. At the time when the peace was concluded Cleombrotus happened to be in Phocis at the head of a Lacedaemonian army; and he now received orders to invade Boeotia without delay. The Thebans on their side, were equally determined on resistance. The two armies met on the memorable plain of Leuctra, near Thespiae. The forces on each side are not accurately known, but it seems probable that the Thebans were outnumbered by the Lacedaemonians. The military genius of Epaminondas, however, compensated any inferiority of numbers by novelty of tactics. Up to this time Grecian battles had been uniformly conducted by a general attack in line. Epaminondas now first adopted the manoeuvre, used with such success by Napoleon in modern times, of concentrating heavy masses on a given point of the enemy's array. Having formed his left wing into a dense column of 50 deep, so that its depth was greater than its front, he directed it against the Lacedaemonian right, containing the best troops in their army, drawn up 12 deep, and led by Cleombrotus in person. The shock was terrible. Cleombrotus himself was mortally wounded in the onset, and with difficulty carried off by his comrades. Numbers of his officers, as well as of his men, were slain, and the whole wing was broken and driven back to their camp. The loss of the Thebans was small compared with that of the Lacedaemonians. Out of 700 Spartans in the army of the latter, 400 had fallen; and their king also had been slain, an event which had not occurred since the fatal day of Thermopylae.

The victory of Leuctra was gained within three weeks after the exclusion of the Thebans from the peace of Callias. The effect of it throughout Greece was electrical. It was everywhere felt that a new military power had arisen - that the prestige of the old Spartan discipline and tactics had departed. Yet at Sparta itself though the reverse was the greatest that her arms had ever sustained, the news of it was received with an assumption of indifference characteristic of the people. The Ephors forbade the chorus of men, who were celebrating in the theatre the festival of the Gymnopaedia, to be interrupted. They contented themselves with directing the names of the slain to be communicated to their relatives, and with issuing an order forbidding the women to wail and mourn. Those whose friends had fallen appeared abroad on the morrow with joyful countenances, whilst the relatives of the survivors seemed overwhelmed with grief and shame.

Immediately after the battle the Thebans had sent to Jason of Pherae in Thessaly to solicit his aid against the Lacedaemonians. This despot was one of the most remarkable men of the period. He was Tagus, or Generalissimo, of all Thessaly; and Macedonia was partially dependent on him. He was a man of boundless ambition, and meditated nothing less than extending his dominion over the whole of Greece, for which his central situation seemed to offer many facilities. Upon receiving the invitation of the Thebans, Jason immediately resolved to join them. When he arrived the Thebans were anxious that he should unite with them in an attack upon the Lacedaemonian camp; but Jason dissuaded them from the enterprise, advising them not to drive the Lacedaemonians to despair, and offering his mediation. He accordingly succeeded in effecting a truce, by which the Lacedaemonians were allowed to depart from Boeotia unmolested.

According to Spartan custom, the survivors of a defeat were looked upon as degraded men, and subjected to the penalties of civil infamy. No allowance was made for circumstances. But those who had fled at Leuctra were three hundred in number; all attempt to enforce against them the usual penalties might prove not only inconvenient, but even dangerous; and on the proposal of Agesilaus, they were, for this occasion only, suspended. The loss of material power which Sparta sustained by the defeat was great. The ascendency she had hitherto enjoyed in parts north of the Corinthian gulf fell from her at once, and was divided between Jason of Pherae and the Thebans. Jason was shortly afterwards assassinated. His death was felt as a relief by Greece, and especially by Thebes. He was succeeded by his two brothers, Polyphron and Polydorus; but they possessed neither his ability nor his power.

The Athenians stood aloof from the contending parties. They had not received the news of the battle of Leuctra with any pleasure, for they now dreaded Thebes more than Sparta. But instead of helping the latter, they endeavoured to prevent either from obtaining the supremacy in Greece, and for this purpose called upon the other states to form a new alliance upon the terms of the peace of Antalcidas. Most of the Peloponnesian states joined this new league. Thus even the Peloponnesian cities became independent of Sparta. But this was not all. Never did any state fall with greater rapidity. She not only lost the dominion over states which she had exercised for centuries; but two new political powers sprang up in the peninsula, which threatened her own independence.

In the following year (B.C. 370) Epaminondas marched into Laconia, and threatened Sparta itself. The city, which was wholly unfortified, was filled with confusion and alarm. The women, who had never yet seen the face of an enemy, gave vent to their fears in wailing and lamentation. Agesilaus, however, was undismayed, and saved the state by his vigilance and energy. He repulsed the cavalry of Epaminondas as they advanced towards Sparta; and so vigorous were his measures of defence, that the Theban general abandoned all further attempt upon the city, and proceeded southwards as far as Helos and Gythium on the coast, the latter the port and arsenal of Sparta after laying waste with fire and sword the valley of the Eurotas, he retraced his steps to the frontiers of Arcadia.

Epaminondas now proceeded to carry out the two objects for which his march had been undertaken; namely, the consolidation of the Arcadian confederation, and the establishment of the Messenians as an independent community. In the prosecution of the former of these designs the mutual jealousy of the various Arcadian cities rendered it necessary that a new one should be founded, which should be regarded as the capital of the confederation. Consequently, a new city was built on the banks of the Helisson, called Megalopolis, and peopled by the inhabitants of forty distinct Arcadian townships. Here a synod of deputies from the towns composing the confederation, called "The Ten Thousand" was to meet periodically for the despatch of business. Epaminondas next proceeded to re-establish the Messenian state. The Messenians had formerly lived under a dynasty of their own kings; but for the last three centuries their land had been in the possession of the Lacedaemonians, and they had been fugitives upon the face of the earth. The restoration of these exiles, dispersed in various Hellenic colonies, to their former rights, would plant a bitterly hostile neighbour on the very borders of Laconia. Epaminondas accordingly opened communications with them, and numbers of them flocked to his standard during his march into Peloponnesus. He now founded the town of Messene. Its citadel was placed on the summit of Mount Ithome, which had three centuries before been so bravely defended by the Messenians against the Spartans. The strength of its fortifications was long afterwards a subject of admiration. The territory attached to the new city extended southwards to the Messenian gulf, and northwards to the borders of Arcadia, comprising some of the most fertile land in Peloponnesus.

So low had Sparta sunk, that she was fain to send envoys to beg the assistance of the Athenians. This request was acceded to; and shortly afterwards an alliance was formed between the two states, in which Sparta waived all her claims to superiority and headship. During the next two years the Thebans continued steadily to increase their power and influence in Greece, though no great battle was fought. In B.C. 368 Pelopidas conducted a Theban force into Thessaly and Macedonia. In Thessaly he compelled Alexander, who, by the murder of his two brothers, had become despot of Pherae and Tagus of Thessaly, to relinquish his designs against the independence of Larissa and other Thessalian cities, and to solicit peace. In Macedonia he formed an alliance with the regent Ptolemy: and amongst the hostages given for the observance of this treaty was the youthful Philip, son of Amyntas, afterwards the celebrated king of Macedon, who remained for some years at Thebes.

In the following year Pelopidas and Ismenias proceeded on an embassy to Persia. Ever since the peace of Antalcidas the Great King had become the recognised mediator between the states of Greece; and his fiat seemed indispensable to stamp the claims of that city which pretended to the headship. The recent achievements of Thebes might entitle her to aspire to that position: and at all events the alterations which she had produced in the internal state, of Greece, by the establishment of Megalopolis and Messene, seemed to require for their stability the sanction of a Persian rescript. This was obtained without difficulty, as Thebes was now the strongest state in Greece; and it was evidently easier to exercise Persian ascendency there by her means, than through a weaker power. The Persian rescript pronounced the independence of Messene and Amphipolis; the Athenians were directed to lay up their ships of war in ordinary; and Thebes was declared the head of Greece.

It was, in all probability, during a mission undertaken by Pelopidas and Ismonias, for the purpose of procuring the acknowledgment of the rescript in Thessaly and the northern parts of Greece, that they were seized and imprisoned by Alexander of Pherae. The Thebans immediately despatched an army of 8000 hoplites and 600 cavalry to recover or avenge their favourite citizen. Unfortunately, however, they were no longer commanded by Epaminondas. Their present commanders were utterly incompetent. They were beaten and forced to retreat, and the army was in such danger from the active pursuit of the Thessalians and Athenians, that its destruction seemed inevitable. Luckily, however, Epaminondas was serving as a hoplite in the ranks. By the unanimous voice of the troops he was now called to the command, and succeeded in conducting the army safely back to Thebes. Here the unsuccessful Boeotarchs were disgraced; Epaminondas was restored to the command, and placed at the head of a second Theban army destined to attempt the release of Pelopidas. Directed by his superior skill the enterprise proved successful, and Pelopidas (B.C. 367) returned in safety to Thebes.

In B.C. 364 Pelopidas again marched into Thessaly against Alexander of Pherae. Strong complaints of the tyranny of that despot arrived at Thebes, and Pelopidas, who probably also burned to avenge his private wrongs, prevailed upon the Thebans to send him into Thessaly to punish the tyrant. The battle was fought on the hills of Cynoscephalae; the troops of Alexander were routed: and Pelopidas, observing his hated enemy endeavouring to rally them, was seized with such a transport of rage that, regardless of his duties as a general, he rushed impetuously forwards and challenged him to single combat. Alexander shrunk back within the ranks of his guards, followed impetuously by Pelopidas, who was soon slain, fighting with desperate bravery. Although the army of Alexander was defeated with severe loss, the news of the death of Pelopidas deprived the Thebans and their Thessalian allies of all the joy which they would otherwise have felt at their victory.

Meantime a war had been carried on between Elis and Arcadia which had led to disunion among the Arcadians themselves. The Mantineans supported the Eleans, who were also assisted by the Spartans; whilst the rest of the Arcadians, and especially the Tegeans, favoured Thebes. In B.C. 362 Epaminondas marched into Peloponnesus to support the Theban party in Arcadia, The Spartans sent a powerful force to the assistance of the Mantineans in whose territory the hostile armies met. In the battle which ensued Epaminondas formed his Boeotian troops into a column of extraordinary depth, with which he bore down all before them. The Mantineans and Lacedaemonians turned and fled, and the rest followed their example. The day was won; but Epaminondas, who fought in the foremost ranks, fell pierced with a mortal wound. His fall occasioned such consternation among his troops, that, although the enemy were in full flight, they did not know how to use their advantage, and remained rooted to the spot. Epaminondas was carried off the field with the spear-head still fixed in his breast. Having satisfied himself that his shield was safe, and that the victory was gained, he inquired for Iolaidas and Daiphantus, whom he intended to succeed him in the command. Being informed that both were slain: "Then" he observed "you must make peace." After this he ordered the spear- head to be withdrawn; when the gush of blood which followed soon terminated his life. Thus died this truly great man; and never was there one whose title to that epithet has been less disputed. Antiquity is unanimous in his praise, and some of the first men of Greece subsequently took him for their model. With him the commanding influence of Thebes began and ended. His last advice was adopted, and peace was concluded probably before the Theban army quitted Peloponnesus. Its basis was a recognition of the STATUS QUO - to leave everything as it was, to acknowledge the Arcadian constitution and the independence of Messene. Sparta alone refused to join it on account of the last article, but she was not supported by her allies.

Agesilaus had lived to see the empire of Sparta extinguished by her hated rival. Thus curiously had the prophecy been fulfilled which warned Sparta of the evils awaiting her under a "lame sovereignty." But Agesilaus had not yet abandoned all hope; and he now directed his views towards the east as the quarter from which Spartan power might still be resuscitated. At the age of 80 the indomitable old man proceeded with a force of 1000 hoplites to assist Tachos, king of Egypt, in his revolt against Persia. He died at Cyrene on his return to Greece. His body was embalmed in wax and splendidly buried in Sparta.