It is a fascinating twist of history that Charles Martel ruled the Franks but was never king. He was offered the title several times by the Pope and by the Frankish lords, but he always refused. It might have been that Martel had personal reservations about breaking his vow to the king. Or, more pragmatically, he might have believed that forcing the king to abdicate would have been destabilizing to his own power. Martel’s authority was derived from his military relationships, and all that kept his armies together was a fragile system of loyalties. If he were to have violated his own sworn loyalty to his king, it might have prompted his generals to revoke their oaths of fealty to him. This dilemma of legitimacy would later be solved by his son, Pepin the Short, who persuaded the church to intercede on his behalf. Rome issued papal bull in 752 AD stating that it was improper that royal power should be exercised by one who rules de facto but is denied the title de juris and that the de facto power should prevail. The decision was as much motivated by political interests as legal reason. Tension between the church and the Lombard dukes who ruled Italy at the time was escalating. When Charlemagne conquered Lombardy in the 770s and rid the church of its adversary, Pope Zachary’s early support of the Carolingian crown was well rewarded. On Christmas day in 800 AD, Pope Leo III, hoping to secure a permanent protector for the church, named Charlemagne Imperator Romanorum, Emperor of the Romans, a title which gave him divine appointment to all of Christendom. While his strength to control so much territory would certainly be challenged, his right to claim it was not. With the blessing of the church and the obedience of a vast army, Charlemagne became perhaps the first king since the Fall of Rome whose rule was undisputed.