Victor IV, born Gregorio Conti was chosen by a party in succession to the antipope Anacletus II (1130–38) on March 13, 1138, but through the influence of Bernard of Clairvaux was induced two months afterwards to make his submission to Pope Innocent II (1130–43). Before his election, Victor IV was known as Cardinal Gregorio Cardinal Conti. Anacletus II, born Pietro Pierloni, (d. ... March 13 is the 72nd day of the year in the Gregorian calendar (73rd in leap years). ... Events Robert Warelwast becomes Bishop of Exeter. ... Saint Bernard of Clairvaux (Fontaines, near Dijon, 1090 â August 21, 1153 in Clairvaux) was a French abbot and the primary builder of the reforming Cistercian monastic order. ... Pope Innocent II (died September 24, 1143), born Gregorio Papareschi, was Pope from 1130 to 1143, and was probably one of the clergy in personal attendance on the antipope Clement III (Guibert of Ravenna). ...
A rival claimant to the papacy who might be elected, appointed, installed, or even proclaim himself to be the legitimate pontiff; such an individual is said by the Church to have assumed the title of pope illegally or in opposition to the legitimate pope.
The antipope was a fairly common occurrence during the Middle Ages, and most were often pathetic Churchmen who were propped up by powerful rulers, such as a Holy Roman Emperor, during a feud with the Holy See over various issues.
Their authority was frequently very limited and, after the resolution of a conflict, the king who created them might convince them to step down or simply abandon them to the whim or caprices of the real successor to St. Peter.