Strabo Geography 8.1.2

[2] There have been many tribes in Greece, but those which go back to the earliest times are only as many in number as the Greek dialects which we have learned to distinguish. But though the dialects themselves are four in number, ¹ we may say that the Ionic is the same as the ancient Attic, for the Attic people of ancient times were called Ionians, and from that stock sprang those Ionians who colonized Asia and used what is now called the Ionic speech; and we may say that the Doric dialect is the same as the Aeolic, for all the Greeks outside the Isthmus, except the Athenians and the Megarians and the Dorians who live about Parnassus, are to this day still called Aeolians. And it is reasonable to suppose that the Dorians too, since they were few in number and lived in a most rugged country, have, because of their lack of intercourse with others, changed their speech and their other customs to the extent that they are no longer a part of the same tribe as before. And this was precisely the case with the Athenians; that is, they lived in a country that was both thin-soiled and rugged, and for this reason, according to Thucydides, ² their country remained free from devastation, and they were regarded as an indigenous people, who always occupied the same country, since no one drove them out of their country or even desired to possess it. This, therefore, as one may suppose, was precisely the cause of their becoming different both in speech and in customs, albeit they were few in number. And just as the Aeolic element predominated in the parts outside the Isthmus, so too the people inside the Isthmus were in earlier times Aeolians; and then they became mixed with other peoples, since, in the first place, Ionians from Attica seized the Aegialus, ³ and, secondly, the Heracleidae brought back the Dorians, who founded both Megara and many of the cities of the Peloponnesus. The Ionians, however, were soon driven out again by the Achaeans, an Aeolic tribe; and so there were left in the Peloponnesus only the two tribes, the Aeolian and the Dorian. Now all the peoples who had less intercourse with the Dorians—as was the case with the Arcadians and with the Eleians, since the former were wholly mountaineers and had no share in the allotments ⁴ of territory, while the latter were regarded as sacred to the Olympian Zeus and hence have long lived to themselves in peace, especially because they belonged to the Aeolic stock and had admitted the army which came back with Oxylus ⁵ about the time of the return of the Heracleidae—these peoples, I say, spoke the Aeolic dialect, whereas the rest used a sort of mixture of the two, some leaning more to the Aeolic and some less. And, I might almost say, even now the people of each city speaks a different dialect, although, because of the predominance which has been gained by the Dorians, one and all are reputed to speak the Doric. Such, then, are the tribes of the Greeks, and such in general terms is their ethnographical division. Let me now take them separately, following the appropriate order, and tell about them.