Matilda de Percy countess of Warwick and magnate (1150–1200) Parents Alice de Tunbridge William de Percy Children Siblings Agnes de Percy Cadwgan ap Cadwaladr ap Gruffudd ap Cynan Rhisiart ap Cadwaladr ap Gruffudd II ap Cynan Alan de Percy Emma de Percy Alice de Percy Walter de Percy Partners William de Beaumont, 3rd Earl of Warwick