Achaean League (əkēˈən) [key], confederation of cities on the Gulf of Corinth. The First Achaean League, about which little is known, was formed presumably before the 5th cent. B.C. and lasted through the 4th cent. B.C. Its purpose was mutual protection against pirates. The Achaeans remained aloof from the wars in Greece until they joined the opposition to Philip II of Macedon in 338 B.C. The confederation was dissolved soon after. The Second Achaean League was founded in 280 B.C. Sicyon was freed from the rule of its tyrant in 251 B.C., and it soon joined the confederation under the leadership of Aratus. Other cities outside Achaea were incorporated on terms of equality, and in 247 B.C. the Macedonians were driven from Corinth. There was some promise of liberating all Greece, but unfortunately the interference of Cleomenes III of Sparta threatened the Achaean League, and in 227 B.C. he began a war. The Achaean League then requested (224 B.C.) Macedonian aid against Sparta and the Aetolian League. The result was the eclipse of the confederation until the wars between Macedon and Rome. In 198 B.C. the Achaeans went over to Rome and with Roman aid won practically the whole Peloponnesus, forcing Sparta and Messene to join. Later suspecting the Achaeans of again looking toward Macedon, the Romans deported (168 B.C.) their leaders (including Polybius) to Italy. In 146 B.C. the Romans waged a war against the Achaeans and easily triumphed at Corinth. The Romans dissolved the confederation, thereby ending Greek liberty.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.