Aetolian League
The Aetolians and the Achaeans developed strong federal states or leagues ("koinon"), which were governed by councils of city representatives and assemblies of league citizens. Initially ethnic leagues, these leagues later began to include cities outside of their traditional regions. The Achaean League eventually included all of the Peloponnese except Sparta, while the Aetolian League expanded into Phocis. During the third century BCE these leagues were able to defend themselves against Macedon and the Aetolian league defeated a Celtic invasion of Greece at Delphi.