Sibylle married Robert "Curthose" de Normandie, Duke of Normandy 1100, Apulia, Italy. Robert (son of William the Conqueror, King of England and Mathilde de Flandre, Queen consort of England, Duchess of Normandy) was born ca. 1053, Normandy, France; died Feb 1134, Cardiff Castle, Cardiff, Wales; was buried , Gloucester Cathedral, Gloucestershire. [Group Sheet]

1. Guillaume I "Clito" de Normandie, Count of Flanders was born 1101, Rouen, Normandy, France; died 27 Jul 1128, Abbey of St Bertin, Saint-Omer, Pas-de-Calais, Hauts-de-France, France; was buried , Abbey of St Bertin, Saint-Omer, Pas-de-Calais, Hauts-de-France, France.