Perhaps two or three centuries may separate Homer from any actual heroic princes of whom traditions have reached him. Modern research holds that the Achaeans of Homer, by infiltration and by conquest, had succeeded to more civilised owners of Greece. But Homer has nothing to say about a conquest of Greece by the Achaeans, Danaans, Argives, and the rest, from the north, except in two cases. He speaks of combats with wild mountain-dwelling tribes in Thessaly, in Nestor's youth. Nestor knew "the strongest of men who warred with the strongest, the mountain-dwelling Pheres,"[1] shaggy folk, says the _Catalogue_, whom Peirithous drove out of Pelion in northern Thessaly, and forced back on the Aethices of Pindus in the west.[2] It appears, from recent excavations, that the age of stone lingered long in these regions, and the people were probably rude and uncultivated, like the Centaurs. The recent excavators of Zerelia, north-east of the Spercheios valley, the home of Achilles, write that their discoveries in the soil "clearly point to the fact that in prehistoric times the cultures of North and South Greece were radically different. This probably indicates an ethnological difference as well."[3] Before the period when "Late Minoan III." pottery occurs in Thessaly, the people used stone tools and weapons, and knew not the potter's wheel. It may not, therefore, be too fanciful to regard Nestor's tales of fights with a wild mountain race as shadowy memories of actual Achaean conquests in Thessaly, where Aegean culture arrived very much later than in Southern Greece. Secondly, Homer twice speaks of regions as "Pelasgian," in which he represents the actual inhabitants as Hellenes and Achaeans, not Pelasgic. These regions are the realm of Achilles in south-west Thessaly; and Epirus.[4] But the actual Pelasgians whom Homer knows are allies of Troy; they dwell on the North Aegean coasts (where Herodotus found living Pelasgians), or reside, with Achaeans, Dorians, True Cretans, and Cydonians, in Crete. These facts indicate Homer's knowledge that, in some regions, Achaeans had dispossessed "Pelasgians," whoever the Pelasgians may have been. Again, Homer makes Achilles address the "Pelasgic Zeus" of Dodona in Epirus, in which he locates Perhaebians and Eneienes.