Beyond that frontier lay a world largely unknown, a mere wilderness of barbarians, tribes always restless, always at war, always pressing upon the confines of civilisation. Within lay all that is worth having in our lives, the hope of the world. It was this which, then as now, had to be defended and against the same enemy--barbarism. For barbarism does not become less barbarous when it becomes learned, a savage is a savage even in professorial dress. For this cause it is written: change your hearts and not your garments. The defence, then, of the frontier had been the chief problem of the Empire perhaps from its foundation by Augustus and certainly for two hundred years before Alaric crossed the Alps. Its solution was attempted in various ways, before, in the year 292, Diocletian attempted to deal with it by the revolutionary scheme of dividing the Empire. But the division he made was, and perhaps unavoidably, rather racial than strategic, the two parts of the Empire met at a critical point on the Danube and by force of geography the eastern part was inclined to an Asiatic outlook and to the neglect of the Danube, while the western was by no means strong enough to hold the tremendous line of the two rivers. Nevertheless the West made an heroic attempt to fulfil its too onerous duty. The capital of the vicariate of Italy was removed from Rome to Milan. This tremendous act was purely strategical. It was thought, and rightly, that the frontier would be more readily secured from Milan, which held, as it were, all the passes of the Alps in its hands, than from Rome in the midst of the long peninsula of Italy. It was a change more amazing than the removal of the capital of the British Empire from London to Edinburgh would be; but it was not enough. In 330, seventeen years after Christianity had become the official religion of the Empire, Constantine the Great for the same reasons of defence removed the seat of the Empire to Byzantium, the new Rome on the Bosphorus, which he renamed Constantinople. That move, which has been so strongly condemned, would seem in any right apprehension of what followed to have saved what could be saved out of the foreseen and perhaps inevitable _débâcle_. Constantinople remained till 1453 the secure capital of the Eastern Government and of a Roman civilisation; it endured, and in more than one critical period held up the citadel of the West--Italy--in its hands.