Elizabeth Mortimer English noblewoman (1371-1417) (1371–1417) Parents Philippa, 5th Countess of Ulster Edmund Mortimer, 3rd Earl of March Children Alice de Camoys Elizabeth Percy Sir Roger de Camoys Henry Percy, 2nd Earl of Northumberland Siblings Edmund Mortimer Philippa de Mortimer Roger Mortimer, 4th Earl of March Partners Thomas de Camoys, 1st Baron Camoys Henry Percy