The lineage of the counts of Perche, extinct by 1217, ending with Thomas. The lineage of the counts of Anjou, who acquired the land by the marriage of a grandson of Fulcois, Geoffrey II of Gâtinais, with Ermengarde of Anjou, heiress of the House of Ingelger, continued on to modern times. Their great-grandson in agnatic line was Geoffrey V of Anjou. The House of Plantagenet descended from this line. Sources Nelson, Janet L., The Annals of St-Bertin, Manchester University Press, 1991 Phalle, Édouard de Saint, Comtes de Troyes et de Poitiers au IXe siècle: histoire d’un double échec. In Christian Settipani and Katharine S. B. Keats-Rohan, Onomastique et Parenté dans l'Occident médiéval. 2000. Kerrebrouck, Patrick van., Nouvelle histoire généalogique de l'auguste maison de France, vol. 1: La Préhistoire des Capétiens. 1993. Tout, Thomas Frederick, The Empire and the Papacy: 918-1273, Periods of European History, London: Rivingtons, 1906 Bachrach, Bernard S, Fulk Nerra, The Neo-Roman Consul, 987-1040: A Political Biography of the Angevin Count, University of California Press, 1993 Bury, J. B. (Editor), The Cambridge Medieval History, Volume III, Germany and the Western Empire, Cambridge University Press, 1922 Bury, J. B. (Editor), The Cambridge Medieval History, Volume V, Contest of Empire and Papacy, Cambridge University Press, 1926 Reuter, Timothy (Editor), The New Cambridge Medieval History, Volume III, 900-1024, Cambridge University Press, 1999 Runciman, Steven, A History of the Crusades, Volume Two, The Kingdom of Jerusalem and the Frankish East, 1100-1187, Cambridge University Press, 1952 Oman, Charles, Periods of European History, Volume I: The Dark Ages, 476-918, Rivingtons, London, 1928 Tout, T. F., Periods of European History, Volume II: The Empire and the Papacy, 918-1273, Rivingtons, London, 1932 Medieval Lands Project, Comtes du Châteaudun Medieval Lands Project, Comtes de Perche Counties of France fr:Liste des comtes et vicomtes de Châteaudun