Antipope Sylvester IV

Sylvester IV
Papacy began	1105
Papacy ended	1111
Predecessor	Adalbert (As Antipope) Paschal II (As Pope)
Successor	Paschal II (As Pope)
Opposed to	Paschal II
Other popes and antipopes named Sylvester

Sylvester IV was a claimant to the papacy from 1105 to 1111.

Members of the Roman aristocracy, with the support of the German king Henry V (1105–25), set up another antipope to replace Pope Paschal II (1099–1118), electing Maginulfo, the Archpriest of St. Angelo in Peschiera, while Paschal II was away from Rome.

After his election Maginulfo took the papal name of Sylvester IV and was consecrated in the Church of St. Maria Rotonda (the Pantheon) and was enthroned in the Lateran on November 18, 1105. When Paschal II returned to Rome the next day, Sylvester IV left for Tivoli and finally settled in Osimo, Province of Ancona, under the protection of Count Guarniero di Ancona. On April 11, 1111 Paschal II and King Henry V reached an agreement about the investiture of Catholic bishops. Then the king, who had used Sylvester IV to exercise pressure on Paschal II, made the antipope abandon his claim to the office of pope and submit to Paschal II. He was allowed to live out the rest of his life in Ancona with Count Guarniero, his patron.