Margaret de Newburg, 7th Countess of Warwick English noble (1250–1253) Parents Philippa Basset Margery de Oilly Henry de Beaumont, 5th Earl of Warwick Children Siblings Thomas de Beaumont, 6th Earl of Warwick Richard (II) Siward Partners John Marshal, Earl of Warwick John du Plessis, 7th Earl of Warwick