Guillaume de Briouze is recorded in lists of those present at the Battle of Hastings. He became the first Lord of Bramber Rape by 1073 and built Bramber Castle. William made considerable grants to the abbey of Saint Florent, Saumur to endow the foundation of Sele Priory near Bramber and a priory at Briouze. He continued to fight alongside King William in the campaigns in Britain, Normandy and Maine.
According to Perfect, a 13th century genealogy in the Bibliothèque de Paris gives the name of his wife as Eve de Boissey, widow of Anchetil de Harcourt. There is a lot of evidence from contemporary charters which supports this view.