Johannes Scotus Eriugena
Probably in the early part of 1050, Berengar addressed a letter to Lanfranc, then prior of Bec Abbey in Normandy, in which he expressed his regret that Lanfranc adhered to the Eucharistic teaching of Paschasius and considered the treatise of Ratramnus on the subject (which Berengar supposed to have been written by Johannes Scotus Eriugena) to be heretical. He declared his own agreement with Eriugena, and believed himself to be supported by Saint Ambrose, Saint Jerome, Augustine, and other authorities. This letter was received by Lanfranc in Rome, where it was read before a council and Berengar's view was condemned. Berengar was summoned to appear at another council to be held at Vercelli in September. Berengar sought permission to go to the council from King Henry I of France, in his capacity as nominal abbot of St. Martin at Tours. Instead, for unclear reasons, the king imprisoned him. The council at Vercelli examined Berengar's doctrine and again condemned it and he was excommunicated.