The ancient imperial city and medieval seat of the Papacy, central to western Christian authority.
Rome was the seat of the papacy and the symbolic center of Latin Christendom throughout the medieval period. The Lateran Palace was the primary papal residence until the papacy's relocation to Avignon in 1309.
Saint Peter's Basilica was the site of major imperial coronations, including Charlemagne's in 800 and the later German emperors' crown-receivings from the pope.
Charlemagne's coronation by Pope Leo III at Saint Peter's on Christmas Day 800 was the defining moment of medieval Roman imperial ideology, creating a western emperor to rival Byzantium and binding the Carolingian and papal projects together — while also creating lasting tensions over relative authority.
The struggle between popes and Holy Roman Emperors over investiture and political authority — most acute during the Investiture Controversy — repeatedly made Rome the symbolic terrain of conflict. Pope Gregory VII's confrontation with Henry IV culminated in the Walk to Canossa in 1077 and Henry's eventual siege of Rome.