Adelolf, Count of Boulogne Count of Boulogne (0891–0933) Parents Ælfthryth, Countess of Flanders Baldwin II Children Arnulf II, Count of Boulogne Mathilde van Vlaanderen, Comtesse de Boulogne Siblings Arnulf I, Count of Flanders Ealswid of Flanders Mathilde van Vlaanderen, Comtesse de St. Pol Ermentrude of Flanders Partners Mathilde de Créquy