Sibyl of Montgomery Peerage person ID=3802 Parents Mabel de Bellême Roger de Montgomerie, 1st Earl of Shrewsbury Children Mabel FitzRobert of Gloucester Siblings Philip de Montgomery Robert of Bellême, 3rd Earl of Shrewsbury Arnulf de Montgomery Hugh of Montgomery, 2nd Earl of Shrewsbury Matilda de Montgomery Roger the Poitevin Roger III de Montgomery Partners Robert Fitzhamon