The aim of this paper is to investigate the image of Archbishop of Braga and Antipope Gregory VIII (1118-1121), Maurice “Bourdin”. Often modern historiography has considered Maurice as only a minor figure of the Church History of the beginning of the 12th century, but a reading of the 12th and 13th century literary sources offers a very different image of him. The use of these kinds of sources and the adoption of a strong international perspective would show how it is possible to rethink Maurice “Bourdin”’s life and career and to revise many features of the Roman Church History and its relations with Hispania in the central centuries of the Middle Ages.