As a general rule, every Greek city-community included in its population, independent of bought slaves, the three elements above noticed,—considerable land proprietors with rustic dependents, small self-working proprietors, and town-artisans,—the three elements being found everywhere in different proportions. But the progress of events in Greece, from the seventh century B. C. downwards, tended continually to elevate the comparative importance of the two latter, while in those early days the ascendency of the former was at its maximum, and altered only to decline. The military force of most of the cities was at first in the hands of the great proprietors, and formed by them; it consisted of cavalry, themselves and their retainers, with horses fed upon their lands. Such was the primitive oligarchical militia, as it was constituted in the seventh and sixth centuries B. C.,[38] at Chalkis and Eretria in Eubœa, as well as at Kolophôn and other cities in Ionia, and as it continued in Thessaly down to the fourth century B. C.; but the gradual rise of the small proprietors and town-artisans was marked by the substitution of heavy-armed infantry in place of cavalry; and a farther change not less important took place when the resistance to Persia led to the great multiplication of Grecian ships of war, manned by a host of seamen who dwelt congregated in the maritime towns. All the changes which we are able to trace in the Grecian communities tended to break up the close and exclusive oligarchies with which our first historical knowledge commences, and to conduct them either to oligarchies rather more open, embracing all men of a certain amount of property, or else to democracies. But the transition in both cases was usually attained through the interlude of the despot. [38] Aristot. Polit. iv, 3, 2; 11, 10. Aristot. Rerum Public. Fragm. ed. Neumann. Fragm. v. Εὐβοέων πολιτεῖαι, p. 112; Strabo, x, p. 447. In enumerating the distinct and unharmonious elements of which the population of these early Grecian communities was made up, we must not forget one farther element which was to be found in the Dorian states generally,—men of Dorian, as contrasted with men of non-Dorian race. The Dorians were in all cases emigrants and conquerors, establishing themselves along with and at the expense of the prior inhabitants. Upon what terms the cohabitation was established, and in what proportions invaders and invaded came together, we are without information; and important as this circumstance is in the history of these Dorian communities, we know it only as a general fact, and are unable to follow its results in detail. But we see enough to satisfy ourselves that in those revolutions which overthrew the oligarchies both at Corinth and Sikyon,—perhaps also at Megara,—the Dorian and non-Dorian elements of the community came into conflict more or less direct.