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
Henry VI the Good a pretext they used the fact that Henry III was directly responsible for the premature death of Henry V (Henry and Bolesław III's father). In the end, Władysław I the Elbow-high managed to capture almost all of Greater Poland, but his allies only took the towns of Uraz (which was given to Henry) and Wołów and Lubiąż (granted to Bolesław III). In 1314 Henry supported his brother-in-law Frederick the Fair of Austria in the battle for the throne of Germany. The war with Głogów began again in 1321. This time, however, Henry wasn't convinced as to the appropriateness of it,