March 13, 1138: Antipope election of Cardinal Gregorio Conti as Victor IV,

 DATELINE: March 13, 1138 – Cardinal Gregorio Conti was elected Antipope as Victor IV, succeeding Anacletus II.

An antipope (Latin: antipapa) is a person who, in opposition to the one who is generally seen as the legitimately elected Pope, makes a significantly accepted competing claim to be the Pope,the Bishop of Rome and leader of the Catholic Church. At times between the 3rd and mid-15th century, antipopes were supported by a fairly significant faction of religious cardinals and secular kings and kingdoms. Persons who claim to be pope, but have few followers, such as the modern sedevacantist antipopes, are not classified with the historical antipopes.

History

Hippolytus of Rome (d. 235) is commonly considered to be the earliest antipope, as he headed a separate group within the Church in Rome against Pope Callixtus I. Hippolytus was reconciled to Callixtus's second successor, Pope Pontian, and both he and Pontian are honoured as saints by the Roman Catholic Church with a shared feast day on 13 August. Whether two or more persons have been confused in this account of Hippolytus and whether Hippolytus actually declared himself to be the Bishop of Rome, remains unclear, since no such claim by Hippolytus has been cited in the writings attributed to him.

Eusebius of Caesarea quotes from an unnamed earlier writer the story of one Natalius, a 3rd-century priest who accepted the bishopric of a heretical group in Rome. This Natalius soon repented and tearfully begged Pope Zephyrinus to receive him into communion.

Novatian (d. 258), another 3rd-century figure, certainly claimed the See of Rome in opposition to Pope Cornelius, and if Natalius and Hippolytus were excluded because of the uncertainties concerning them, Novatian could then be said to be the first antipope.

The period in which antipopes were most numerous was during the struggles between the popes and the Holy Roman Emperors of the 11th and 12th centuries. The emperors frequently imposed their own nominees to further their own causes. The popes, likewise, sometimes sponsored rival imperial claimants (antikings) in Germany to overcome a particular emperor.

The Great Western Schism— which began in 1378, when the French cardinals, claiming that the election of Pope Urban VI was invalid, elected Clement VII as Pope— led to two, and eventually three, rival lines of claimants to the papacy: the Roman line, the Avignon line (Clement VII took up residence in Avignon, France), and the Pisan line. The Pisan line was named after the town of Pisa, Italy, where the (Pisan) council had elected Alexander V as a third claimant. To end the schism, in May 1415, the Council of Constance deposed John XXIII of the Pisan line. Pope Gregory XII of the Roman line resigned in July 1415. In 1417, the Council also formally deposed Benedict XIII of Avignon, but he refused to resign. Afterwards, Pope Martin V was elected and was accepted everywhere except in the small and rapidly diminishing area that remained faithful to Benedict XIII. The scandal of the Great Schism created anti-papal sentiment, and fed into the Protestant Reformation at the turn of the 16th century.

List of historical antipopes

Pontificate	Common English name	Regnal (Latin) name	Personal name	Place of birth	Age at Election / Death or Resigned	# years as Antipope	Notes	In opposition to
c. 200	Natalius	Natalius					Later reconciled (see above)	Zephyrinus
217–235	Saint Hippolytus	Hippolytus					Later reconciled with Pope Pontian (see above)	Callixtus I
								Urban I
								Pontian
251–258	Novatian	Novatianus					Founder of Novatianism	Cornelius
								Lucius I
								Stephen I
								Sixtus II
355–365	Felix II*	Felix secundus					Installed by Roman Emperor Constantius II	Liberius
366–367	Ursicinus	Ursicinus	Ursinus					Damasus I
418–419	Eulalius	Papa Eulalius						Boniface I
498–499 501–506	Laurentius	Papa Laurentius					Supported by Byzantine emperor Anastasius I	Symmachus
530	Dioscorus	Papa Dioscurus						Boniface II
687	Theodore	Papa Theodorus						Sergius I
687	Paschal (I)	Papa Paschalis
767–768	Constantine II	Papa Constantinus secundus						Stephen III
768	Philip	Papa Philippus					Installed by envoy of Lombard King Desiderius
844	John VIII	Papa Joannes octavus					Elected by acclamation	Sergius II
855	Anastasius III Bibliothecarius	Papa Anastasius tertius						Benedict III
903–904	Christopher	Papa Christophorus						Between Leo V and Sergius III
974	Boniface VII	Papa Bonifacius septimus						Between Benedict VI and Benedict VII
984–985								Between John XIV and John XV
997–998	John XVI*	Papa Joannes sextus decimus	John Filagatto				Supported by Byzantine emperor Basil II	Gregory V
1012	Gregory VI	Papa Gregorius sextus						Benedict VIII
1058–1059	Benedict X*	Papa Benedictus decimus	John Mincius				Supported by the Counts of Tusculum	Nicholas II
1061–1064	Honorius II	Papa Honorius secundus	Pietro Cadalus				Supported by Agnes, regent of the Holy Roman Empire	Alexander II
1080, 1084–1100	Clement III	Papa Clemens tertius	Guibert of Ravenna				Supported by Henry IV, Holy Roman Emperor	Gregory VII
								Victor III
								Urban II
								Paschal II
1100–1101	Theodoric	Papa Theodoricus					Successor to Clement III	Paschal II
1101	Adalbert or Albert	Papa Adalbertus					Successor to Theodoric
1105–1111	Sylvester IV	Papa Sylvester quartus	Maginulf				Supported by Henry V, Holy Roman Emperor
1118–1121	Gregory VIII	Papa Gregorius octavus	Maurice Burdanus					Gelasius II
								Callixtus II
1124	Celestine II	Papa Cœlestinus secundus	Thebaldus Buccapecus					Honorius II
1130–1138	Anacletus II	Papa Anacletus secundus	Pietro Pierleoni					Innocent II
1138	Victor IV	Papa Victor quartus	Gregorio Conti				Successor to Anacletus II
1159–1164	Victor IV	Papa Victor quartus	Ottavio di Montecelio				Supported by Frederick I, Holy Roman Emperor	Alexander III
1164–1168	Paschal III	Papa Paschalis tertius	Guido di Crema
1168–1178	Callixtus III	Papa Callixtus tertius	Giovanni of Struma
1179–1180	Innocent III	Papa Innocentius tertius	Lanzo of Sezza
1328–1330	Nicholas V	Papa Nicolaus quintus	Pietro Rainalducci				Supported by Louis IV, Holy Roman Emperor	John XXII
1378–1394	Clement VII	Papa Clemens septimus	Robert of Geneva	Geneva	36/52	15 y, 11 m, 27 d	Avignon	Urban VI
								Boniface IX
1394–1423	Benedict XIII	Papa Benedictus tertius decimus	Pedro de Luna	Illueca, Aragon	66/95	28 y, 7 m, 25 d	Avignon
								Innocent VII
								Gregory XII
								Martin V
1409–1410	Alexander V*	Papa Alexander quintus	Pietro Philarghi				Pisa	Gregory XII
1410–1415	John XXIII	Papa Joannes vicesimus tertius	Baldassare Cossa				Pisa
1423–1429	Clement VIII	Papa Clemens octavus	Gil Sánchez Muñoz				Avignon	Martin V
1424–1429	Benedict XIV	Papa Benedictus quartus decimus	Bernard Garnier
1430–1437	Benedict XIV	Papa Benedictus quartus decimus	Jean Carrier
								Eugene IV
1439–1449	Felix V	Papa Fœlix quintus	Duke Amadeus VIII of Savoy	Chambéry, Savoy	56/65 (†67)	9 y, 5 m, 2 d	Elected by the Council of Basel
								Nicholas V

Source: Wikipedia