History of the Peloponnesian War

Indeed, even after the Trojan war Hellas was still subject to migrations and in process of settlement, and hence did not get rest and wax stronger.

For not only did the return of the Hellenes from Ilium, occurring as it did after a long time, cause many changes; but factions also began to spring up very generally in the cities, and, in consequence of these, men were driven into exile and founded new cities.