The sharp, fierce struggle between Greek and Persian which was fought out on land and sea in the years 480–479, was regarded by those who were contemporary with it, and has ever since been looked upon as the great crisis in the history of the two races. It was a struggle whose results were decisive in the history of the world. From a purely military point of view, it is true, the fighting in those two years was not final. The loser did not issue from it in a condition so crippled that he could not continue the contest. So far from this being the case, Persia, for more than a century after Salamis was fought, continued not merely to show a bold front to Greece, but to maintain the preponderance of her power in the lands east of the Ægean, and to be a cause of dread to the Hellene of Europe. Athens did, in the period succeeding these great years of the war, wrest from Persia most of the Hellenic or semi-Hellenic Islands and coast towns in the Eastern Ægean; but her tenure of many of them was brief, and of all, precarious. The city States on the mainland slip rapidly from her grasp, and the measure of the independence from Persia in the case of some of those who remain on the tribute lists is at least open to discussion. It was long before the Greek world discovered that decay of the great Empire which is so apparent to the student of history who has the story of the fifth and fourth centuries before him. It set in soon after 479; but how far it was caused by the festering of the wounds inflicted in that year cannot now be said. The mischief was internal: it was situate far away in the depths of Asia, beyond the ken of the Greek of the fifth century, and it is not strange that he never appreciated the full extent of the malady. And yet there is even a military point of view, from which the warfare of these years _was_, in a sense, decisive. From that time forward Persia was the assailed and not the assailant. The Great King either was not, or did not feel himself in a position to assume the offensive beyond the waters which separated Asia from Europe. In reckoning up the results of a great war it is instructive to appreciate what was: it is impossible to ignore what might have been. Of the issues, military, political, and social, of this Græco-Persian war, the military issue is perhaps the least important from the point of view of world-history. It did, indeed, teach a great lesson, in that it brought into prominence for the first time the strength and weakness of the East and West when brought into contact with one another; but the most extraordinary feature about this special aspect of the matter is that those who had tried the tremendous experiment were all but utterly unconscious of the true bearing of its results; and it was left to the fourth generation from them to appreciate a truth which their forefathers had proved but never realized.