Matilda de Flandre Peerage person ID=42573 Parents Sibylla of Anjou Thierry of Lorraine, Count of Flanders Children Siblings Philip I, Count of Flanders Matthew of Alsace Peter of Flanders Gertrude of Flanders, Countess of Savoy Margaret I, Countess of Flanders Baldwin de Flandre Laurette of Flanders