Federal state of ancient Aetolia in central Greece, probably based on a looser tribal community.
A leading power by с 340 BC, the Aetolian League resisted invasions by Macedonia in 322 and 314–311, expanded into Delphi, and allied with Boeotia с 300. It fended off the Gaul s in 279 and formed an alliance with Macedonia (с 270–240). The league's power in central Greece was confirmed with the defeat of the Boeotians (245). From the late 3rd century Aetolia began to lose power and territory to Macedonia, culminating in the sacking of the league's federal capital, Thermum, by Philip V in 220. The league then allied with Rome against Macedonia and defeated Philip at Cynoscephalae (197). Rome later forced it into a permanent alliance (189) that cost it territory, power, and independence.