Third Period of History - Persian Invasion
By this splendid victory the naval power of Persia was almost annihilated, and the spirit of its monarch so completely humbled, that he durst no longer undertake offensive operations against Greece. Here, therefore, the war ought to have terminated; but so great and valuable had been the spoils obtained by the confederate forces, that they were unwilling to relinquish such a profitable contest. The war, therefore, was continued for twenty years longer, less, apparently, for the chastisement of Persia, than for the plunder of her conquered provinces.
But now that all danger was over, many of the smaller states, whose population was scanty, began to grow weary of the contest, and to furnish with reluctance their annual contingent of men to reinforce the allied fleet. It was, in consequence, arranged that those states whose citizens were unwilling to perform personal service, should send merely their proportion of vessels, and pay into the common treasury an annual subsidy, for the maintenance of the sailors with whom the Athenians undertook to man the fleet. The unforeseen but natural consequence of this was the establishment of the complete supremacy of Athens. The annual subsidies gradually assumed the character of a regular tribute, and were compulsorily levied as such; while the recusant communities, deprived of their fleets, which had been given up to the Athenians, were unable to offer effectual resistance to the oppressive exactions of the dominant state. The Athenians were thus raised to an unprecedented pitch of power and opulence, and enabled to adorn their city, to live in dignified idleness, and to enjoy a constant succession of the most costly public amusements, at the expense of the vanquished Persians, and of' the scarcely more leniently-treated communities of the dependent confederacy.