Achaenas, in ancient history, the name of one of the main divisions of the Hellenic race. Originally they dwelt in Thessaly, whence they migrated to the Peloponnesus, of which they were the ruling nation in the heroic period. Their name is therefore mentioned in the Iliad as a generic term for the Greeks. The well-greaved Achaeans, the long-haired Achaeans, are terms employed to designate the whole Hellenic host before Troy. Their mvthological ancestor was Achaeus, son of Xuthus, and grandson of Hellen.