The democracy consistently supported the victorious Thebans against Sparta, figuring with a large contingent on the decisive field of Mantineia (362).
By throwing in her lot with the Peloponnesian democracies and Athens, Argos seriously endangered Sparta's supremacy, but the defeat of Mantineia (418) and a successful rising of the Argive oligarchs spoilt this chance.
About 469 B.C. Mantineia alone of Arcadian townships refused to join the league of Tegea and Argos against Sparta.
Not only were cities called after him, medals struck with his effigy, and statues erected to him in all parts of the empire, but he was raised to the rank of the gods, temples were built for his worship in Bithynia, Mantineia in Arcadia, and Athens, festivals celebrated in his honour and oracles delivered in his name.
After the battle of Leuctra the philo-Laconian party was expelled with Mantineian help. Tegea henceforth took an active part in the revival of the Arcadian League and the prosecution of the war in alliance with Thebes against Sparta (371-362), and the ultimate defection of Mantineia confirmed it in its federalist tendencies.
About 235 B.C. Mantineia entered the Achaean League, from which it had obtained protection against Spartan encroachments, but soon passed in turn to the Aetolians and to Cleomenes III.
The worship and mysteries of Cora at Mantineia were famous.
In contrast with the Macedonian sympathies of Megalopolis Mantineia joined the leagues against Antipater (322) and Antigonus Gonatas (266).
The demiurgi among other officials represent Elis and Mantineia at the treaty of peace between Athens, Argos, Elis and Mantineia in 420 B.C. (Thuc. v.
Thus Arcadia lagged behind the general development of Greece, and its political importance was small owing to chronic feuds between the townships (notably between Mantineia and Tegea) and the readiness of its youth for mercenary service abroad.