The Encyclopedia Americana (1920)/Achæi

ACHÆI, ak-ī′ē, ACHAIANS, ak-ā-yans, or ACHÆANS, ak-e′ans, the descendants of the mythical Achæus, son of Xuthus and grandson of Helen; a generic term employed by Homer to designate the whole Hellenic host before Troy, and in poetic use applied to all the Greeks indiscriminately. They appear to have been that batch of the Greeks which inhabited southeastern Thessaly and northern Peloponnesus, and by the Dorian invasion were driven altogether beyond the Corinthian Gulf and cooped into a strip of Peloponnesus along its southern shore, where they were the nucleus of the later Achaian League. See.