Guillaume de Montfort, also known as Guillaume of Hainaut, was a French nobleman of the end of the 10th century, the first Lord of Montfort-l'Amaury. He was succeeded as Lord of Montfort-l'Amaury by his son Amaury I de Montfort. Guillaume is possibly the son of Amaury, Count of Valenciennes. Bibliography Lords of France Guillaume Guillaume 10th-century births 11th-century deaths Year of birth unknown Year of death unknown References