Gen 25 de Clare (Isabel)

Gilbert I de Clare (b. 1182 Hertford, Hertfordshire, England - d. October 25, 1230 Penrhôs, Monmouth, Wales) Earl of Gloucester

Isabel Marshall (b. October 9, 1200 Pembroke Castle, Pembroke, Dyfed, Wales - d. December 17, 1239 Berkhampstead, Hertfordshire, England) Countess of Cornwall

children: Avicia, Richard, Agatha, Isabel, Adeliza, William, Gilbert II

• Richard Plantagenet (b. January 5, 1209 Winchester, Hampshire, England - d. April 2, 1272 Berkhampstead, Hertfordshire, England) Earl of Cornwall
  
  1. Sancha Berenger (b. 1225 Aix-En-Provence, Bouches-Du-Rhone, France - d. November 9, 1261 Berkhampstead, Hertfordshire, England) Countess of Provence
     children: Richard II, Walter, Edmund
     
  2. Beatrix van Valkenburg (b. abt 1248 Sittard, Limburg, Netherlands - d. October 17, 1277 Friars Minor, Oxford, Oxfordshire, England)
     
  3. Joan de Valletort (b. abt 1209 Castle Trematon, Cornwall, England)
     
  
  
• (unknown)