Aetolia, a western division of the mainland of Greece, on the N. shore of the gulf of Corinth or of Lepanto, W. of Doris and Lo-cris, and E. of Acarnania, and divided by the narrow strait between Rhium and Anti-Rhium from Achaia. It is bounded W. by the Achelous, now the Aspropotamo, and N. by Thessaly and Epirus. Its chief city in antiquity was Thermus, in the interior, on the river Evenus, now Fidhari. Aetolia is said to have been originally settled in the ante-heroic times by the Curetes, who were conquered by the hero Aetolus, son of Endymion, with a band of followers from Elis, in the Peloponnesus. During the mythic and heroic ages Aetolia was distinguished as the seat of many of the richest and most poetical of the legends of early Greece. In the days of Thucydides, however, the Aetolians were still a barbarous and uncouth tribe. During the Peloponnesian war they played no considerable part, nor do they appear prominently in Greek history until nearly a century later. On the death of Philip of Macedon and the accession of Alexander (336 B. C), the Aetolians displayed such hostility to the latter as drew down his signal vengeance. According to Pausa-nias, Greece owed much to the Aetolians for their energy in beating back the Gallic hordes.

With this exception, the Aetolians seem to have fought on any side to which the hope of plunder allured them. With Alexander of Epirus, the son of Pyrrhus, they formed a coalition for the sake of dismembering Acarnania for their own advantage; and again they banded themselves with Cleomenes III. of Sparta, hoping to overthrow the Acluean league. After the death of Antigonus Doson of Macedon (220), they carried their arms into the Peloponnesus in a series of predatory incursions, for which they were severely chastised by Philip V., the successor of Antigonus, who sacked and destroyed their capital, Thermus. In the latter years of the second Punic war the Romans were hard set to avert the consequences of the alliance between Hannibal and Philip V. of Macedon; the Aetolians, with their allies, attached themselves to the Romans, and enabled them, by the employment of a small naval squadron, and a trifling body of forces under the praetor Laevinus, to neutralize all the preparations of Philip, until they had rid themselves of their principal opponent on the field of Zama (202). At the battle of Cynoscephalae (197) their cavalry greatly distinguished itself, charging home ten times against the Macedonians, who were at first victorious, and giving the consul Flamininus time to bring up his reserves and convert a half-lost day into a complete victory.

For this they expected to reap their reward in the dismemberment of Philip's dominions; but it was denied to them by the Romans. The Aetolians now attempted an alliance against their late allies with Antiochus the Great of Syria, who had been prompted to hostilities against Rome by Hannibal; but after a single defeat by the Roman consul Glabrio in the pass of Thermopyhe (191), the latter retreated into Asia, leaving his Greek confederates to the mercy of the enemy. The polity of the Aetolians from this time, and indeed before, consisted of a federal government similar to the Acluean league, at one time embracing a number of neighboring territories; but being swallowed up with the rest of Greece in the universal empire of Rome (146), Aetolia followed her fortunes, and afterward shared the reverses of the eastern empire. Possessed on the irruption of the barbarians by Slavic hordes, Aetolia was reconquered and partially civilized, together with the Illyrians and Dalmatians, by the Venetians during the middle ages, and subsequently became, like the Morea, the scene of deadly conflict against the victorious Turks. In later times it fell under the power of Ali Pasha of Albania, and it was the scene of some of the most important events of the Greek revolution. - The principal seaport town of modern Aetolia is Missolonghi. The climate is delicious, but along the seacoast and the swampy river shores the autumnal season is marked by fevers.

The plains are rich and fertile in maize, wine, silk, and fruits; the mountain scenery is magnificent. (See Acarnania.)