433 BC

Events

Pericles concludes a defensive alliance with Corcyra (Corfu), the strong naval power in the Ionian Sea, which is the bitter enemy of Corinth. As a result, Athens intervenes in the dispute between Corinth and Corcyra, and, at the Battle of Sybota, a small contingent of Athenian ships play a critical role in preventing a Corinthian fleet from capturing Corcyra. Following this, Athens places Potidaea, a tributary ally of Athens but a colony of Corinth, under siege.
The Corinthians, upset by Athens’ actions, lobbies Sparta to take action against Athens. This appeal is backed by Megara (which is being severely affected by Pericles' economic sanctions) and by Aegina (which is being heavily taxed by Pericles and which has been refused home rule).
Pericles renews alliances with the Rhegium on the south west corner of Italy and Leontini in south-east Sicily, threatening Sparta's food supply route from Sicily.