On Christmas day 800 Charlemagne was crowned Roman Emperor by Pope Leo III. The ceremony took place at St. Peter's in Rome.
Charlemagne was hailed as a new Constantine and a new Augustus. Carolingians exploited the models presented by the Roman Imperial tradition to support Charlemagne's claim of an Imperium Christianum under his authority.
Charlemagne was King of the Franks, and for a brief time, the undisputed ruler of Western Europe. He was a promoter of civilization in the Dark Ages.
Europe was in state of near anarchy and had all but forgotten the value of education. Charlemagne established a central government over Western Europe, restoring much of the unity and order of the old Roman Empire.
Charlemagne established his court at Aachen and gathered together scholars to make his court a center of learning. Charlemagne ordered old sagas of the Franks be written.
Charlemagne promoted the expansion and administration of his kingdom by the use of local counts overseen by his representatives. A revival and reform of learning and the church took place (the Carolingian Renaissance) under Charlemagne directed by an Anglo-Saxon Benedictine named Alcuin.
In 800 A.D. there was a rebellion in Rome against the Pope. Charlemagne called for a trial, but the trial could neither condemn the Pope or find him innocent.
Charlemagne and his men battled with the Saxons and their leader Widukind. After one of Widukind's attacks, Charlemagne ordered the execution of 4500 Saxon prisoners in one day.
Charlemagne united most of what is western Europe and his impact was felt long after his death. A cult dedicated to him formed over 300 years after his death.
Charlemagne was devoutly religious. He had a reported interest in holy relics and asked the Pope about a rumor of a relic with Christ's blood.