2020. Di Vito Loré, Marina C. Sarramia (2019). "Stefano VI, papa." Dizionario Biografico degli Italiani Volume 94 (Treccani: 2019). Popes Italian popes Bishops of Anagni Year of birth missing 897 deaths 9th-century archbishops 9th-century popes Deaths by strangulation Heads of government who were later imprisoned Burials at St. Peter's Basilica