Foundations (in Greek old Πλάταια / Plátaia , more often in the plural Πλαταιαί / Plataiaí ) is a quoted of Béotie on the northern slope of the Cithéron, in the south-west of Thèbes, which plays a big role at the time of the medic Guerres. An offering is drawn up in Delphes to commemorate the battle (see serpentine Colonne).

It flies to the help of Athens in 490 av. J. - C. and nearly a thousand of its citizens take part in the battle of Marathon. In 479 av. J. - C. the Greeks directed by Lacédémonien Pausanias and the Athenian Aristide beat completely the Persian general Mardonios at the time of the large last battles terrestrial of the medic Wars, the battles of Foundations. Throughout fifth century BC, Platéens defend with eagerness their independence against the hegemonic will of Thèbes allied of Sparte. Between 429 av. J. - C. and 427 av. J. - C. they support three years a heroic seat and only make themselves constrained by the famine. Sparte makes shave the city and of many Platéens take refuge with Athens where they receive the established among.

The Peace of Antalcidas in 386 av. J. - C. authorizes them, at least their descendants, to rebuild their city but this one is again destroyed by Thèbes in 373 av. J. - C. and its inhabitants know a new exile in Athens. The city is rebuilt after the victory of Chéronée in 338 av. J. - C. and especially after the confusion of Thèbes by Alexandre Large the in 335 av. J. - C.. However she does not play any more any big role in the history of Greece.