Background
She was a daughter of Roger Mortimer, 1st Earl of March and Joan de Geneville, Baroness Geneville.
She was a daughter of Roger Mortimer, 1st Earl of March and Joan de Geneville, Baroness Geneville.
Agnes Mortimer was one of the twelve children of Roger Mortimer, 1st Earl of March and Joan de Geneville, Baroness Geneville. Her paternal grandparents were Edmund Mortimer, 2nd Baron Mortimer and Margaret de Fiennes. Her maternal grandparents were Piers de Geneville, of Trim Castle and Ludlow, and Jeanne of Lusignan.