Guillaume I Hainaut de Montfort, Lord of Montfort, was born circa 955 to Rodolphe de Hainaut (c922-aft966) and died circa 1011 of unspecified causes. He married Fille de Beauvais . Charlemagne (747-814)/s.
Sources agree that Guillaume de Montfort was a grandson of Regnier II de Hainaut, but not a son of Regnier III. It is not known whether Guillaume was a son of Rodolphe (as shown here), of Liethard, or of a fourth son called Amaury.
|Offspring of Guillaume I de Montfort and Fille de Beauvais|
|Amaury I de Montfort (c990-1053)||990||1053||Bertrade de Gometz|