The main source is a Vita of the monk Raoul Glaber, a novice who accompanied William and who sometimes regarded his master as a rival, but also as a mentor who encouraged his work as a chronicler.

[1] William was born on the family citadel on the island of San Giulio, Lake Orta, Novara, Piedmont.

The fourth son of Count Robert, in 969, at the age of seven, he began his education at the Benedictine abbey at Locadio, Vercelli.

In 1001, he was called to rebuild the destructed Abbey of Fécamp[citation needed] (present-day department of Seine-Maritime) by Richard II,[2] where the Dukes of Normandy had their palace and had chosen to be buried.

He designed the Romanesque church of the abbey, daringly placing the transept crossing at the top of the mount.