Diocletian was foredoomed to failure. The Empire had trusted to a professional army recruited from a comparatively small section of its inhabitants, and when this army succumbed to the strain of civil war and foreign invasion, and the old recruiting-grounds were wasted, few of the provinces in the interior, which for nearly two centuries had practically ceased to furnish soldiers, held any reserve of military material. By admitting this and calling upon the barbarian to occupy and defend the wasted frontier lands, the civilization of the ancient world showed that it had lost the vitality which might have assimilated these new elements as Gaul, Spaniard, and Africa had been assimilated in the past. A succession of able rulers and the overpowering prestige of the past kept the framework intact for a century after Diocletian's death. Then when the final catastrophe came, and the Western provinces sank into the Dark Ages, a national revival headed by the still virile races of Asia Minor saved the once despised provinces of the East from being involved in a common ruin. It is with Zeno the Isaurian, not with Diocletian, that the true renascence of the Empire begins.
But the auxiliary regiments which survived into the fourth century need not only suggest to us, by the smallness of their numbers and their isolation among their barbarian comrades, the nearness of the end. The reflection that many of these regiments had held the position assigned to them and preserved a continuous military record for over three hundred years may serve also to remind us of the greatness of the services rendered by the army of the Empire to the cause of civilization.
