Eustace IV, Count of Boulogne Eustace IV, Count of Boulogne Eustace IV (c. 1127–1135 – 17 August 1153), Count of Boulogne, was the eldest son of King Stephen of England and Countess Matilda I of Boulogne. When his father seized the English throne on Henry I's death in 1135, he became heir apparent to the English throne. Upon his mother's death in 1152 he inherited the county of Boulogne and other estates. Eustace was first mentioned in one of his parents' charters dated no later than August 1131. As heir to the English throne in 1137, he did homage for Normandy to Louis VII of
English claims to the French throne female inheritance finally had to be introduced. On the death of Philip IV the Fair's son Louis X in 1316, immediately followed by that of his son John I the Posthumous, it had to be decided whether his young daughter Joan or his brother Philip would succeed to the throne. Philip arranged for his coronation, and became Philip V of France. He was challenged by the supporters of the Princess Joan, daughter of Louis X, on the basis of his right to the throne. In response, he convened an assembly of prelates, barons, and burgesses at Paris, who acknowledged him