William appealed to King Henry I of France, who gave him in marriage Adelaide, the heiress of the county of Soissons.[2] Adelaide was daughter of Renaud I, Count of Soissons and Grand Master of the Hotel de France. William then became Count of Soissons in right of his wife. William and Adelaide had five children:
Crouch, David (2002). The Normans: The History of a Dynasty. Hambledon Continuum.
Douglas, David (1946). "The Earliest Norman Counts". The English Historical Review. 61 (240 May). Oxford University Press.
Newman, William Mendel (1971). Les seigneurs de Nesle en Picardie (XIIe-XIIIe siècle): Recueil des Chartes (in French). Edition A. & J. Picard.
Baron de Reiffenberg (1848). Godefroid de Bouillon, suite du Chevalier au cygne: avec des recherches sur ... Brussels: Academie Royale de Belgique. p. 142.