The Lombard king felt that his opportunity was slipping by, and acted with some vigour. He captured Ravenna and threatened Rome. The Pope hurried across the Alps. He anointed and crowned Pippin; he likewise anointed and blessed his son Charles (Charlemagne), and forbade the Franks under pain of excommunication ever to choose their king from any other family. These three great favours, the transfer of the royal title, the coronation rite, and the perpetual confirmation of the Carlovingian sovereignty, called for a great return. Pippin promised that the Adriatic provinces, taken by the Lombards from the Byzantines, should be ceded by the Lombards to the Pope. This promise Pippin fulfilled. He crossed the Alps, defeated the Lombard king, and forced him to cede the Exarchate of Ravenna and the five cities below it on the coast, to the Pope, who thereby became an actual sovereign. Thus Pippin discharged his obligation to the Papacy. This beginning of the Papal monarchy is so important that the theoretic origin may as well be mentioned here. There was a legend, universally believed, that an early Pope, Silvester (314-335) healed the Emperor Constantine of leprosy, and that the Emperor, in gratitude, made a great grant of territory to the Pope. The fact appears to have been that Constantine, although not cured of the leprosy, did give to Silvester the Lateran palace and a plot of ground around it. This little donation grew in legend like a grain of mustard seed, and served the purpose of the Roman clergy. No good Roman would have been content with a title derived from the Lombards or the Franks. In Roman eyes these Barbarians never had any title to Italian territory; they could give none. The only possible source of legal title was the Empire. In the gift by Constantine to Silvester papal adherents had a foundation of fact. That was enough. It is quite unnecessary to imagine false dealing. People in those days believed that what they wished true was true. This legend was accepted and embodied in concrete form in a document known as the _Donation of Constantine_, which is so important in explaining the attitude of the Papacy throughout the Middle Ages, that it may be quoted:--