Pope Adrian I was the bishop of Rome and ruler of the Papal States from 1 February 772 to his death. He was the son of Theodore, a Roman nobleman.

Charlemagne was King of the Franks from 768, King of the Lombards from 774, and Emperor of what is now known as the Carolingian Empire from 800, holding all these titles until his death in 814. Charlemagne succeeded in uniting the majority of Western Central Europe, and was the first recognized emperor to rule in the west after the fall of the Western Roman Empire approximately three centuries earlier. Charlemagne's rule saw a program of political and social changes that had a lasting impact on Europe in the Middle Ages.