Question: Who is the maternal grandmother of William, Count Of Sully?
Sentence (from "Adela of Normandy"): Adela of Normandy, of Blois, or of England (c. 1067 – 8 March 1137), also known as in Roman Catholicism, was a daughter of William the Conqueror and Matilda of Flanders who later became the Countess of Blois, Chartres, and Meaux by marriage to Stephen II, Count of Blois.
Relevant evidence: Yes