Henry III supported the papal pretension of Antipope Benedict XIII. He was later canonised by Antipope Paschal III. The Council deposed the antipope and his followers. Benedict VIII was opposed by an antipope, Gregory VI, who compelled him to flee Rome. In 1164, Frederick Barbarossa made Viterbo the seat of his antipope Paschal III. Antipope Clement III still occupied St. Peter's. The Jews suffered much from the relentless persecutions of the Avignon-based antipope Benedict XIII. Nevertheless, Henry V chose another antipope, Gregory VIII. He was succeeded by Antipope Callixtus III. The building contains the monumental tomb of Antipope John XXIII by Donatello and Michelozzo Michelozzi. Leo VIII was established as an antipope by Otto at this time. Never, however, did Vratislaus link his fate with that of Henry's antipope, Clement III. Roger supported Antipope Anacletus II against Innocent II. Other sources classify him as an antipope. Another Coptic (Alexandrian) Antipope is known to have laid claim in the fourth century.