As his marriage to Isabel de Warenne, Countess of Surrey had been childless, Marie, his only surviving sibling, succeeded as the suo jure Countess of Boulogne.
Dat fiind că mariajul acestuia cu Isabela de Warenne nu a produs copii, Maria, singura soră supraviețuitoare a sa, a succedat ca suo jure contesă de Boulogne.