Exact dates are uncertain in early church records, but tradition holds that the first Pope, St Peter, reigned from 41 until his death in Nero’s Rome in 67. The papacy grew in importance after the co-option of Christianity by the Emperor Constantine in the Edict of Milan in 313, which allowed them to exercise their religion freely.
In times of weakness the papacy became something of a hot potato, particularly in the 9th and 10th centuries. Muslims of the Abbasid Caliphate looted Rome in 846 and the church at the time seemed to be awash with corruption. Following the establishment of the Holy Roman Empire in 962 the papacy was under Germanic domination and frequently changed hands.
With the rise of the size and scope of the church, the role of Pope became hotly contested. The first anti-pope – a Pope declared in opposition to the canonically elected Pope – appeared in 251, when Novatianus emerged as a rival to Pope Cornelius (251-53) and the three following Popes. Thereafter every century until the 13th featured at least one anti-pope, with the 11th and 12th centuries being particularly fractious (seven and 10 anti-popes, respectively). After a brief respite in the relatively stable 13th century, three anti-popes were declared in each of the 14th and 15th century. The last anti-pope was Felix V of Savoy, who resigned his claim to the papacy in 1449.
The chart below illustrates the distribution of Popes and anti-popes from the beginnings of the Christian church to the present. (Notes: the 1st century consists of 59 years from 41 to 100 AD; some individuals were counted in more than one century if their term of office overlaps centuries; in the 11th century Benedict IX was Pope on three separate occasions, one of which was regarded as an anti-papacy – he is counted for each. He is the only Pope to have sold the papacy).
The rise of modern medicine from the 17th century onwards assisted in lengthening the reigns of Popes, in part contributing to the 19th century being the most stable period in the church’s history in terms of its leadership. The entire century only featured six Popes, in part due to the 31-year reign of Pius IX from 1846 to 1878, which is the longest papal term of office in history.
The chart below sets out the average term of office of canonically elected Popes in each century. It illustrates the longevity of the 19th century Popes (average term 16.5 years) and the chaotic environment of the 10th century (average term 4.3 years), in which 23 Popes and 3 anti-popes jostled for the church’s top job.
Isaac Asimov, Asimov’s Chronology of the World, London, 1991.
Mark Hillary Hansen (ed.), Kings, Rulers and Statesmen, New York, 2nd edn., 2005.