Charles himself goes to Rome in November…

Charles himself goes to Rome in November 800, and on December 1 holds a council here with representatives of both sides.

Leo, on December 23, takes an oath of purgation concerning the charges brought against him, and his opponents are exiled.

Charlemagne's father, Pepin, had defended the papacy against the Lombards and issued the Donation of Pepin, which had granted the land around Rome to the pope as a fief.

In 774, Pope Adrian I had conferred on Charles his father’s dignity of Patricius Romanus, which implied primarily the protection of the Roman Church in all its rights and privileges, above all in the temporal authority which it had gradually acquired (notably in the former imperial Duchy of Rome and the Exarchate of Ravenna) by just titles in the course of the two preceding centuries.

Few moments in world history prove to be of greater significance than what transpires in St. Peter's Basilica in Rome on Christmas Day in the year 800, when, two days after Leo's oath, he crowns Charles as Roman emperor.

According to Charlemagne's biographer, Einhard (Vita Caroli 28), Charles had no suspicion of what was about to happen, and if informed would not have accepted the imperial crown.

On the other hand, there seems no reason to doubt that for some time previous the elevation of Charles had been discussed, both at home and at Rome, especially in view of two facts: the scandalous condition of the imperial government at Constantinople, and the acknowledged grandeur and solidity of the Carolingian house.

This represents, in theory, the reestablishment, after a hiatus of more than three centuries, of a Roman empire with two rulers -- one in Rome and one in Constantinople.

In fact, Charles rules from Aachen, not Rome, and the Imperial Greeks view the Germanic emperor as a usurper.

The coronation offends Constantinople, which sees itself still as the rightful defender of Rome, but the Eastern Roman Empress Irene of Athens, like many of her predecessors since Justinian, is too weak to offer protection to the city or its much reduced citizenry.

Thus does Charlemagne, wise though illiterate, pious but ruthless, become the father of Europe.