How did Louis I’s coronation in 816 affect the pope’s role in imperial coronations?

The coronation of Louis I by Pope Stephen IV in 816 significantly bolstered the papacy’s influence over imperial authority. While Louis had already been crowned by his father, Charlemagne, in 813 at Aachen—a ceremony deliberately designed to exclude the pope and emphasize Frankish control—Stephen IV’s act of anointing Louis in Reims established a new precedent.12

By performing this ceremony, the papacy positioned itself as the essential agency responsible for creating emperors. This act of anointing and crowning became one of the papacy’s most valued prerogatives, reinforcing the theory that the pope held the power to confer imperial status. This event intensified the long-standing conflict between the papal view, which asserted that the pope constituted the emperor, and the Frankish view, which sought to maintain imperial independence from the Roman see.21