Ancient Greek city in southwest Peloponnese, Greece, founded in 369 BC after the defeat of Sparta by Athens. The site includes with Megalopolis, Mantineia, and Argos; the summit of Mt. Ithómi served as the acropolis. The classical city withstood several Macedonian and Spartan sieges. After the Battle of Chaeronea in 338 BC, it was absorbed into the domain of Philip II of Macedonia, and it remained important under the Romans. The Hellenistic agora, theater, stadium, Temple of Artemis, city walls, and council chamber have been excavated.