The Italian monk and theologian Lanfranc (ca. 1010-1089) served as archbishop of Canterbury. He was a trusted adviser of King William I and presided over many changes in the English Church after the Norman conquest.

Anative of Pavia, Lanfranc migrated to France in the 1030s. He studied under Bérenger at Tours and taught at Avranches. In 1042 he became a monk at Bec; he rose to be prior and head of the monastic school, which became famous under his direction. At the councils of Rome and Vercelli in 1050 Lanfranc was the principal defender of orthodoxy against the heretical doctrine of Bérenger on transubstantiation. His own views were expounded later in his treatise De corpore et sanguine Domini (On the Body and Blood of the Lord), which, like his other theological work, is sound but unoriginal.

William, Duke of Normandy (later William I of England), made...