A city north of Potidaea on the mainland of the Chalcidic peninsula (see chalcidice). Originally Bottiaean, it became a Greek city after its capture by Persia (479 bc) and repopulation from Chalcidice; its position and mixed population made it the natural centre of Greek Chalcidice against attacks from Athens, Macedon, and Sparta. In 433 the city was strengthened by further migration and received territory from Macedon, and it soon became the capital of a Chalcidian Confederacy issuing federal coinage (see federal states). In the end Olynthus fell to Philip II of Macedon by treachery and was destroyed (348). Excavations have revealed the layout of the city (see urbanism).