(b Rome; elected 795; d Rome, June 12, 816; can 1673; fd 12 June).
Saint, pope, and patron. His pontificate was particularly important in the context of the Carolingian Renaissance, owing to his copious building activity and the impetus that he gave to the art of mosaic. His is the longest biography in the Liber pontificalis. His election as pope was disputed by factions of the Roman lay nobility. In 799 he sought the protection of Charlemagne at Paderborn, returning in triumph to Rome to crown him Emperor of the Romans in Old St Peter’s on Christmas night 800.
The political implications of the coronation of Charlemagne as Emperor and the recently produced ‘Donation of Constantine’ (a forged document granting extensive papal powers in the Italian peninsula) were given figurative expression in the mosaic (destr.) over the central apse of the first triclinium (banqueting hall) built by Leo in the Lateran Palace. An 18th-century reproduction exists in the niche overlooking the Piazza di S Giovanni in Laterano, next to the Scala Santa. The ...