Charlemagne (Carolus Magnus in Latin) and Carloman were sons of Pippin, the King of the Franks. When the father died, his two sons came to rule territories of equal worth. Upon Carloman’s death, Charlemagne inherited the rest of the lands. At this time, the Lombards (a Germanic people originally from Northern Europe) constantly invaded the Papal States. (A note about the Papal States: for a period of time the pope was not only spiritual ruler of the Church but also a temporal ruler. After the disintegration of the Roman Empire by attacks from the Goths and Vandals, territory around Rome came under the rule of the popes, hence the term Papal States. The emperor had moved years before to Constantinople, which was the seat of the Eastern Empire. In the West, smaller kingdoms developed. The Papal States remained in existence until the unification of Italy beginning in the 1870s. They officially came to an end with the Lateran Treaty, in which Mussolini recognized the area around the Vatican as a separate country.)
Pope Hadrian appealed to Charlemagne for help with the Lombard problem. Charlemagne crossed the Alps and defeated them. After his victory, he went to Rome and received many honors from the pope. This interference of Charlemagne had its good and bad consequences in the Church. The first good consequence was that the Pope’s enemies were defeated and any future enemies of the Papal States would have to fight the Frankish Empire. Second, a newly founded religion from Arabia (Islam) was beginning to sweep through northern Africa and into Spain. With centralization of power under Charlemagne and the expansion of his kingdom, Christianity could be protected.
There were bad consequences as well. Charlemagne did not know how to separate government from Church business. He constantly meddled with Church affairs and saw it as his right to do so. He micromanaged everything, from the appointing of a bishop to a diocese to accepting candidates to the monastery. From a military and even political point of view, the pope was at the mercy of the king. Later, when there would be numerous Catholic monarchs from different countries, this would also prove to be a disadvantage. What side would the papacy take?
In any event, the successor to Hadrian, Pope Leo III, was viciously attacked in 799 by enemies to the papacy and almost left for dead. Once again, Charlemagne came to the rescue by giving the pope a body guard. Later, he traveled to Rome and attended Christmas Mass at Saint Peter’s Basilica, where Pope Leo III crowned him Emperor. Charlemagne was hailed the new Emperor of the Holy Roman Empire, which was a vestige of the old Roman Empire, and was given the right to be present at Papal elections and the right to hold authority over the city of Rome and the Papal States.