Peter of Bruys (also known as Pierre De Bruys or Peter de Bruis; fl. 1117 – c.1131) was a medieval French religious teacher. He was called a heresiarch (leader of a heretical movement) by the Roman Catholic Church because he opposed infant baptism, the erecting of churches and the veneration of crosses, the doctrine of transubstantiation and prayers for the dead. An angry Roman Catholic mob murdered him in or around 1131. Information on Peter of Bruys is derived from two extant sources, the treatise of Peter the Venerable against his followers and a passage written by Peter Abelard. Life and teachings Sources suggest that Peter was born at Bruis, in southeastern France. The history of his early life is unknown, but he was a Roman Catholic priest who had been deprived of his office by the Church hierarchy for teaching unorthodox doctrine. He began his preaching in Dauphiné and Provence, probably between 1117 and 1120. The local bishops, who oversaw the dioceses of Embrun, Die, and Gap, suppressed his teachings within their jurisdictions. In spite of the official repression, Peter's teachings gained adherents at Narbonne, Toulouse and in Gascony. Peter admitted the doctrinal authority of the Gospels in their literal interpretation but considered the other New Testament writings to be valueless, as he doubted their apostolic origin. He questioned the Old Testament and rejected the authority of the Church Fathers and that of the Roman Catholic Church itself. Petrobrusians also opposed clerical celibacy, infant baptism, prayers for the dead and organ music. Treatise of Peter the Venerable In the preface to his treatise that attacked Peter of Bruys, Peter the Venerable summed up the five teachings that he saw as the errors of the Petrobrusians. Also known as Peter of Montboissier, he was an abbot and an important religious writer who became a popular figure in the church, an internationally-known scholar and an associate of many national and religious leaders of his day. The first "error" was their denial "that children, before the age of understanding, can be saved by the baptism... According to the Petrobrusians, not another's, but one's own faith, together with baptism, saves, as the Lord says, 'He who will believe and be baptized will be saved, but he who will not believe will be condemned.'" That idea ran counter to the medieval Church's teaching, particularly in the Latin West, following the theology of Augustine, in