To the great good fortune of Agis, a pressing message now arrived announcing the imminent revolt of Tegea, the most important ally of Sparta, and close upon her border. Such was the alarm occasioned by this news that the whole military population instantly started off to relieve the place, Agis at their head, the most rapid movement ever known to have been made by Lacedæmonian soldiers.[110] When they arrived at Orestheium in Arcadia, in their way, perhaps hearing that the danger was somewhat less pressing, they sent back to Sparta one-sixth part of the forces, for home defence, the oldest as well as the youngest men. The remainder marched forward to Tegea, where they were speedily joined by their Arcadian allies. They farther sent messages to the Corinthians and Bœotians, as well as to the Phocians and Lokrians, invoking the immediate presence of these contingents in the territory of Mantineia. The arrival of such reinforcements, however, even with all possible zeal on the part of the cities contributing, could not be looked for without some lapse of time; the rather, as it appears, that they could not get into the territory of Mantineia except by passing through that of Argos,[111] which could not be safely attempted until they had all formed a junction. Accordingly Agis, impatient to redeem his reputation, marched at once with the Lacedæmonians and the Arcadian allies present, into the territory of Mantineia, and took up a position near the Herakleion, or temple of Hêraklês,[112] from whence he began to ravage the neighboring lands. The Argeians and their allies presently came forth from Mantineia, planted themselves near him, but on very rugged and impracticable ground, and thus offered him battle. Nothing daunted by the difficulties of the position, he marshalled his army and led it up to attack them. His rashness on the present occasion might have produced as much mischief as his inconsiderate concession to Thrasyllus near Argos, had not an ancient Spartan called out to him that he was now merely proceeding “to heal mischief by mischief.” So forcibly was Agis impressed either with this timely admonition, or by the closer view of the position which he had undertaken to assault, that he suddenly halted the army and gave orders for retreat, though actually within distance no greater than the cast of a javelin from the enemy.[113] [110] Thucyd. v, 64. ἐνταῦθα δὴ βοήθεια τῶν Λακεδαιμονίων γίγνεται αὐτῶν τε καὶ τῶν Εἱλώτων πανδημεὶ ὀξεῖα καὶ οἵα οὔπω πρότερον. The out-march of the Spartans just before the battle of Platæa (described in Herodot. vii, 10) seems, however, to have been quite as rapid and instantaneous. [111] Thucyd. v, 64. ξυνέκλῃε γὰρ διὰ μέσου. [112] The Lacedæmonian kings appear to have felt a sense of protection in encamping near a temple of Hêraklês, their heroic progenitor (see Xenophon, Hellen. vii, 1, 31).