The foundations of Megalopolis were hardly laid when Agesilaus undertook an expedition in the hope of breaking up the union of which it was the visible sign and capital. He accomplished nothing, and had hardly reached home when the Thebans and their allies under Epaminondas and Pelopidas entered the Peloponnesus and marched through Laconia almost unopposed. After the departure of Epaminondas, Lycomedes of Mantinea succeeded in drawing the Arcadian federation away from its alliance with Thebes, in consequence of which it had to make common cause with Athens An attempt on the part of the federation to use the treasures of the temple of Zeus at Olympia led to internal dissensions, so that in the battle of Mantinea (362) one half of the Arcadians fought on the side of the Spartans, the other on that of the Thebans. After this battle many of the inhabitants of Megalopolis sought to return to their former homes, and it was only by the assistance of three thousand Thebans under Pammenes that the authorities were able to prevent them from doing so. In the year 352, when Thebes had her hands full with the so-called Sacred War, the Spartans made an attempt to reduce Megalopolis; but the Thebans promptly sent assistance, and the city was rescued. Not sure of this assistance, the Megalopolitans had appealed to Athens, an aj>peal which gave occasion to Demosthenes’s oration ∏∈pl tΛeyaKoιtoKιτωv. The Spartans were now obliged to conclude peace with Megalopolis and acknowledge her autonomy. Nevertheless their feeling of hostility did not cease, and Megalopolis consequently entered into friendly relations with Philip of Macedon. Twenty years later, when the Spartans and their allies rebelled against the power of Macedon, Megalopolis remained firm in its allegiance, and was subjected to a siege of considerable duration. After the death of Alexander, Megalopolis was governed by native tyrants. In the war between Cassander and Polysperchon it took part with the former, and was, in consequence, besieged by the latter. On this Occasion it was able to send into the field an army of fifteen thousand. In 234 b.c. Lydiades, the last tyrant of Megalopolis, voluntarily resigned his power, and the city joined the Achaean league. In consequence of this it was once more exposed to the bitteι hatred of Sparta. In 222 Cleomenes took and plundered it, and killed or dispersed its inhabitants, but in the year following it was restored and its inhabitants reinstated by Philopoemen, a native of the city At this time the circuit of its walls always too great, seems to have been contracted. At all events it never again attained political importance, and gradually sank into insignificance. The only great men whom it produced were Philopoemen and Polybius the historian. Lycortas, the father of the latter, may be accounted a third In the time of Pausanias the city was mostly in ruins.