Very soon after the capture of Pavia, Charles was back again on the Rhine, as the affairs of North Germany required his immediate attention. It was perhaps in part from the scantiness of his leisure, but it was surely in part also from his statesmanlike insight into the conditions of the problem before him, that he made so little change in the internal constitution of his new kingdom. There was no attempt to amalgamate the regions north and south of the Alps: Italy did not become a part of “Francia,” but Charles took his place as successor of the long line of kings from Alboin to Desiderius who had reigned over Lombard Italy. “Rex Francorum et Langobardorum atque Patricius Romanorum”: that was now his full title. As King of the Franks he ruled the wide regions north of the Alps: as King of the Lombards he ruled all of Italy that the Lombards had once held: as Patrician of the Romans he seems to have been recognized as supreme ruler of all the rest of Italy except the little fragments on the coast which still held by their allegiance to the eastern emperor. What, then, during the years of transition between 774 and 800, were his relations to that eastern emperor? Some answer to this question will be given in a subsequent chapter. And what were his relations to the pope, in those territories in which his or his father’s donation had taken effect? A question almost impossible to answer. Never was there a more striking case of that phenomenon of the Middle Ages to which M. Guizot has drawn attention, the co-existence of two opposing theories of law without any apparent perception of their discord in the minds of the men who had to carry them into practice. But though both Charles and the pope are spoken of as sovereigns in these territories it appears probable--we cannot say more--that Hadrian, had he been closely questioned on the subject, would have recognized that even in the duchy of Rome he was, in a manner difficult to define, subject to the over-lordship of the Frankish king. As has been said, the conduct of Charles in reference to the kingdom of Italy, if that of an ambitious man, was on the whole wise and statesmanlike. This praise can hardly be given to his relations to the papacy, in which there was a want of that clear and frank statement of what was granted and what was withheld, which is the only means of avoiding future misunderstandings between the giver and the receiver of a benefit. And the consequences of this omission weighed heavily on Europe for centuries, and often involved two really upright and honest men, a Pope and an Emperor, in hopeless quarrels.