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
Stephen, King of England Robert of Gloucester rebelled against the King, starting the descent into civil war in England. An illegitimate son of Henry I and the half-brother of the Empress Matilda, Robert was one of the most powerful Anglo-Norman barons, controlling estates in Normandy as well as the Earldom of Gloucester. He was known for his qualities as a statesman, his military experience, and leadership ability. Robert had tried to convince Theobald to take the throne in 1135; he did not attend Stephen's first court in 1136 and it took several summons to convince him to attend court at Oxford later that year.