Title: Das päpstliche Amtsverständnis Nikolaus' I. in seiner Briefkorrespondenz
Subjects: Popes, Primacy, History of doctrines, Schism, Eastern and Western Church
People: Nicholas I Pope (approximately 800-867), Photius I Saint, Patriarch of Constantinople (approximately 820-approximately 891), Lothair II King of Lorraine (approximately 825-869), Michael III Emperor of the East (836-867)
Time periods: Middle Ages, 600-1500