History of the Peloponnesian War

Such were then the navies of the Greeks, both ancient and modern. Nevertheless, such as applied themselves to naval business gained by them no small power, both in revenue of money and in dominion over other people. For with their navies (especially those men that had not sufficient land, where they inhabited, to maintain themselves) they subdued the islands.

But as for war by land, such as any state might acquire power by, there was none at all; and such as were, were only between borderer and borderer. For the Grecians had never yet gone out with any army to conquer any nation far from home, because the lesser cities neither brought in their forces to the great ones as subjects nor concurred as equals in any common enterprise; but such as were neighbours warred against each other hand to hand.

For the war of old between the Chalcideans and the Eretrians was it wherein the rest of Greece was most divided and in league with either party.