Athens: Its Rise and Fall Book I Vol I

I. The return of the Heraclidae occasioned consequences of which the most important were the least immediate. Whenever the Dorians forced a settlement, they dislodged such of the previous inhabitants as refused to succumb. Driven elsewhere to seek a home, the exiles found it often in yet fairer climes, and along more fertile soils. The example of these involuntary migrators became imitated wherever discontent prevailed or population was redundant: and hence, as I have already recorded, first arose those numerous colonies, which along the Asiatic shores, in the Grecian isles, on the plains of Italy, and even in Libya and in Egypt, were destined to give, as it were, a second youth to the parent states.

II. The ancient Greek constitution was that of an aristocracy, with a prince at the head. Suppose a certain number of men, thus governed, to be expelled their native soil, united by a common danger and common suffering, to land on a foreign shore, to fix themselves with pain and labour in a new settlement -- it is quite clear that a popular principle would insensibly have entered the forms of the constitution they transplanted.