Since the middle of the nineteenth century the study of history has undergone changes no less sweeping than those which have in the same time affected the study of the physical sciences. Vast groups of facts distributed through various ages and countries have been subjected to comparison and analysis, with the result that they have not only thrown fresh light upon one another, but have in many cases enabled us to recover historic points of view that had long been buried in oblivion. Such an instance was furnished about twenty-five years ago by Dr. Bryce's epoch-making work on the Holy Roman Empire. Since then historians still recognize the importance of the date 476 as that which left the Bishop of Rome the dominant personage in Italy, and marked the shifting of the political centre of gravity from the Palatine to the Lateran. This was one of those subtle changes which escape notice until after some of their effects have attracted attention. The most important effect, in this instance, realized after three centuries, was not the overthrow of Roman power in the West, but its indefinite extension and expansion. The men of 476 not only had no idea that they were entering upon a new era, but least of all did they dream that the Roman Empire had come to an end, or was ever likely to. Its cities might be pillaged, its provinces overrun, but the supreme imperial power itself was something without which the men of those days could not imagine the world as existing. It must have its divinely ordained representative in one place if not in another. If the throne in Italy was vacant, it was no more than had happened before; there was still a throne at Constantinople, and to its occupant Zeno the Roman Senate sent a message, saying that one emperor was enough for both ends of the earth, and begging him to confer upon the gallant Odovakar the title of patrician, and entrust the affairs of Italy to his care. So when Sicambrian Chlodwig set up his Merovingian kingdom in northern Gaul, he was glad to array himself in the robe of a Roman consul, and obtain from the eastern emperor a formal ratification of his rule.