House of Blois chose a wife from the House of Champagne (Adela of Champagne) as a counterpoise to Angevin power. The senior line of the House of Blois became extinct with the death of Joan I of Navarre, wife of Philip IV of France, in 1305. Champagne and Navarre passed to the Capetian dynasty. King Stephen I of England, 1135–1154, was both a member of the House of Blois and the last Anglo-Norman King, being the grandson of William the Conqueror through his daughter Adela of Normandy. A branch of the family was established in Sancerre by Stephen I of Sancerre, a younger
Emma of Blois Emma of Blois Emma of Blois ( 950–27 December 1003) was Duchess consort of Aquitaine by marriage to William IV, Duke of Aquitaine. She ruled Aquitaine as regent for her son, William V, Duke of Aquitaine, from 996 until 1004. She was the daughter of Theobald I, Count of Blois and Luitgarde of Vermandois. In 968, she married William IV, Duke of Aquitaine. His overindulging in hunting and women offended her greatly. Around 996, he retired to a monastery. During the course of her marriage, she founded the monastery of Saint Peter in Bourgueil. Emma then ruled Aquitaine as regent