William de Forz married Christina, daughter of Alan of Galloway, by 1234, and became earl of Albemarle (or Aumale) in 1241. His second marriage was to Isabella, sister of Baldwin de Redvers, earl of Devon. She died in 1293.
Barbara English, ‘Forz , William de, count of Aumale (b. before 1216, d. 1260)’, Oxford Dictionary of National Biography, Oxford University Press, 2004 [http://www.oxforddnb.com/view/article/29480, accessed 16 March 2010]