Margaret de Mortimer Peerage person ID=129629 (d. 1297) Parents Maud de Braose, Baroness Wigmore Roger Mortimer, 1st Baron Mortimer Children Sir Thomas de Vere Siblings Roger Mortimer de Chirk Edmund Mortimer, 2nd Baron Mortimer Sir Geoffrey Mortimer Sir William Mortimer Isabella Mortimer, Countess of Arundel Ralph Mortimer Partners Robert de Vere, 6th Earl of Oxford