 His father assumed the name Mortemer after being given the possession of the castle and village of Mortemer in the Pays de Bray, called sometimes "Morte-mer sur Eaulne" or "en Brai".However, after the Battle of Mortemer of 1054, Roger lost the land and was banned from Normandy for his failure to capture an enemy of the Duke William.Decades later, the property was granted back to the Mortemer family, namely by Ranulph, who acquired it.