Eustace of Boulogne may refer to one of these four Counts of Boulogne: Eustace I of Boulogne r. 1045–1049, son of Count Baldwin II of Boulogne and Adelina of Holland Eustace II of Boulogne ( – ), count of Boulogne from 1049 to 1087 and companion of William the Conqueror Eustace III of Boulogne, count of Boulogne, son of Eustace II of Boulogne and Ida of Lorraine Eustace IV of Boulogne ( – 1153), Count of Boulogne and son and heir of Stephen of England