Princess Adelaide of Normandy (c. 1026 in Calvados, France - c. 1090) was the sister of William the Conqueror. She was the daughter of Robert the Magnificent, Duke of Normandy, and Harlette de Falaise. Adelaide married three times; first Enguerrand II of Ponthieu (died 1053) by whom she had no issue; second Lambert II, Count of Lens (died 1054); and third Odo II of Champagne son of the Count of Troyes. By Lambert she had a daughter, Judith of Lens, who married Waltheof, … Wikipedia
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