Members of this family held the important castles of Bellême, Alençon, Domfront and Sées as well as extensive lands in France, Normandy and Maine.

[2] Yet in a charter to the abbey of Lonlay of the lands of Neustria Pia, he describes himself as William princeps and provinciae principatum gerens indicating he considered himself an independent ruler or prince of his own domains.

[7] He wandered until he was taken in by the de Montgomery family whose son Roger agreed to marry his daughter Mabel in return for the lands William lost.

[8] Mabel inherited all the vast estates of her father (and in 1079 those of her uncle Bishop Ives) and married the heir of one of the most prominent families in Normandy, Roger de Montgomery, who became the 1st Earl of Shrewsbury.

[10] Robert had also acquired the countship of Ponthieu jure uxoris and the honor of Tickhill; all of which combined made him the wealthiest magnate in both England and Normandy.

Seinfroy (Seginfredus) sought the bishopric of Le Mans and offered Geoffrey I, Count of Anjou the hamlet of Coulaines and the villa of Dissay-sue-Courcillon including all fiscal rights if he could use his influence.

[19] He had married a Hildeburg, daughter of a nobleman named Arnulf, but he had his wife strangled on her way to church, according to Orderic, because she loved God and would not support his wickedness.

Suspecting nothing, fitz Giroie, while a guest at the festivities, was suddenly seized by Talvas' men and imprisoned, then according to Orderic horribly mutilated and blinded before being released.

[20] Of all of Orderic's female subjects William's daughter Mabel was the most cunning and treacherous; if not entirely for her own misdeeds then as the mother of Robert de Bellême, who had a reputation for savagery as well as cruelty.

Southern could well apply to Robert de Bellême as well: "His life was given over to military designs, and to the raising of money to make them possible; for everything that did not minister to those ends he showed a supreme contempt".