The twelve Achaean cities of the northern Peloponnese had organized a league by the fourth century BCE to protect themselves against piratical raids from across the Corinthian Gulf, but this league had fallen apart after the death of Alexander the Great.
The ten surviving cities—Dyme, Patrae, Tritaea, and Pherae; joined by Aegium, Bura, and Cerynea—renew their alliance in 280 BCE.
This second, more powerful Achaean league, headed now by a single general instead of two, comprises the cities of Achaea and most of the rest of the Peloponnesus except for Corinth, which remains a Macedonian possession, and Sparta, which remains independent.
Annual voting for leadership is by cities, with representation proportionate to population.
Patras (Greek: Patrai), an important commercial center located on the northern shore of the Peloponnesus, about one hundred miles (one hundred and eighty kilometers) west of Athens, is the primary city among the league’s Peloponnesian participants.