It was a large proportion of the best strength of the commonwealth that, after so great a loss in the battle, remained in a danger not in the moment to be calculated. Every exertion therefore was to be made to save it. Of six moras, into which for military purposes the Lacedæmonian people were divided, the men of four, within thirty years after boyhood (such was the term, meaning perhaps the age of about fourteen), had marched under Cleombrotus; those however being excepted who bore at the time any public office. The ephors now ordered the remaining two moras to march, together with those of the absent moras, to the fortieth year from boyhood, and no longer allowing exception for those in office. The command, Agesilaus being not yet sufficiently recovered to take it, was committed to his son Archidamus. Requisitions were at the same time hastened off for the assistance of the allies: and the Lacedæmonian interest, or the interest adverse to the pretensions and apprehended purposes of Thebes, prevailed so in Tegea, Mantinea, Phlius, Corinth, Sicyon, and throughout the Achæan towns, that from all those places the contingent of troops was forwarded with alacrity.
Meanwhile the leading Thebans, meaning to pay a compliment that might promote their interest in Athens, had hastened thither information of their splendid success. But the impression made by this communication was not favourable to their views: on the contrary, it showed that the jealousy, formerly entertained so generally among the Athenians towards Lacedæmon, was already transferred to Thebes. Thus the incessant quarrels among the Grecian republics, source indeed of lasting glory to some, brought however, with their decision, neither lasting power nor lasting quiet to any; but, proving ever fertile in new discord, had a constant tendency to weaken the body of the nation. Relief to Lacedæmon in its pressing danger came, not from its own exertion, not from the interest which all the Grecian republics had in preventing Thebes from acquiring that overbearing dominion with which in a Lacedæmon had oppressed them, but from a power newly risen, or revived, in a corner of the country whence, for centuries, Greece had not been accustomed to apprehend anything formidable.
Jason of Pheræ in Thessaly was one of those extraordinary men in whom superior powers of mind and body sometimes meet. He was formed to be a hero had he lived with Achilles: and as a politician he could have contended with Themistocles or Pericles. He had the advantage of being born to eminence in his own city, one of the principal of Thessaly; and he appears to have acquired there a powerful popularity. Little informed of the early part of his life, we find him mentioned as general of the Pheræans about six years before the battle of Leuctra, and commanding a force sent to assist Neogenes, chief of Histiæa in Eubœa. In the contests of faction in Thessaly it was become common to employ mercenary troops. Jason excelled in diligence in training such troops, in courage and skill in commanding them, and in the arts by which he attached them to his interest.
Of the state of Thessaly at this time altogether we may form some judgment from what the contemporary historian [Xenophon] has related of Pharsalus, one of its most considerable cities. The leaders of the factions by which Pharsalus was torn, weary at length of ruinous contest, came to an extraordinary agreement. Fortunately they had a fellow-citizen, Polydamas, eminent throughout Thessaly for high birth, large possessions, and that splendid hospitality for which the Thessalians were distinguished, but yet more singularly eminent for integrity. To this man the Pharsalians committed the command of their citadel and the exclusive management of their public revenue, giving him altogether a princely authority. In so extraordinary an office Polydamas had the good fortune to succeed in everything, except in opposing the ambition of the too politic and powerful Jason.