The Pan-Ionian sanctuary of Poseidon on the Asiatic promontory of Mycale was regarded as perpetuating a cult from Peloponnesian Achaea, and the league of twelve cities which maintained it, as imitated from an Achaean dodecapolis, and as claiming (absurdly, according to Herodotus i.
He invaded Attica at the head of the Peloponnesian forces in the summers of 43 1, 430 and 428, and in 42 9 conducted operations against Plataea.
The combined complaints of the injured parties led Sparta to summon a Peloponnesian congress which decided on war against Athens, failing a concession to Megara and Corinth (autumn 432).
In his adoption of a purely defensive policy at the beginning of the Peloponnesian War, he miscalculated the temper of the Athenians, whose morale would have been better sustained by a greater show of activity.
The inhabitants sided with Athens during the Peloponnesian War, and during the Roman invasion their city was of considerable importance.