from the poverty of its soil
Thucydides, 1.2 — the independence of Attica, and the birth of the city
It is evident that the country now called Hellas had in ancient times no settled population; on the contrary, migrations were of frequent occurrence, the several tribes readily abandoning their homes under the pressure of superior numbers. Without commerce, without freedom of communication either by land or sea, cultivating no more of their territory than the necessities of life required, destitute of capital, never planting their land (for they could never tell when an invader might not come and take it all away, and when he did come they had no walls to stop him), thinking that the necessities of daily sustenance could be supplied at one place as well as another, they cared little about shifting their habitation, and consequently neither built large cities nor attained to any other form of greatness. The richest soils were always most subject to this change of masters; such as the district now called Thessaly, Boeotia, most of the Peloponnesus (Arcadia excepted), and the most fertile parts of the rest of Hellas. The goodness of the land favored the enrichment of particular individuals, and thus created faction which proved a fertile source of ruin. It also invited invasion. Accordingly Attica, from the poverty of its soil enjoying from a very remote period freedom from faction, never changed its inhabitants. And here is no minor example of my assertion that migrations were the cause of there being no correspondent growth in other parts. The most powerful victims of war or faction from the rest of Hellas took refuge with the Athenians as a safe retreat; and it an early period, becoming naturalized, swelled the already large population of the city to such a height that Attica became at last too small to hold them, and they had to send out colonies to Ionia.