The siege of Plataea took place in 429–427 BC, during the Peloponnesian War. At the beginning of the conflict, the Thebans attacked the city of Plataea, an Athenian ally on the border between Boeotia and Attica. The initial Theban attempt to capture the city failed, but in 429 BC the Thebans' allies, the Spartans under their king Archidamus II, laid siege to the city. Left unaided by Athens, the Plataeans finally surrendered in 428 BC. Plataea was razed to the ground by the Thebans, and was not restored until after 338 BC by Philip II of Macedon.