William, Count of Sully

Wilhelm ( * 1090/93, † 1150 ) was a Count of Blois and Chartres out of the house Blois. He was the eldest son of Count Stephan ( Heinrich) of Blois and Adela of Normandy. Mother's side he was the eldest grandson of William the Conqueror.

Wilhelm followed his fallen on the crusade in 1102 father as Count of Blois and Chartres, but as he was still a minor at the time he was under the guardianship of his mother. Around the year 1106/ 07 he was deposed at the instigation of his mother in favor of the younger brother Theobald as Count, because he allegedly suffered a mental illness.

Wilhelm was ultimately only the possession of the castle of Sully, to which he was passing through its closed around 1100 marriage with their heiress, Agnes de Sully and held that his descendants until the 14th century. His children were:

• Archambaud II ( Odo ) of Sully
• Raoul de Sully († 1177 ), Abbot of Cluny
• Henry of Sully ( † after 1188 ), abbot of Fécamp
• Margaret of Sully; ∞ with Count Henry I of Eu
• NN daughter, Abbess of Sainte- Trinité in Caen