William de Berkeley, 1st Marquess of Berkeley English peer (1426–1492) Parents James Berkeley, 1st Baron Berkeley Isabel de Mowbray Children Sir Thomas Berkeley Katherine Berkeley Siblings unknown daughter Berkeley Maurice Berkeley, 3rd Baron Berkeley unknown daughter Berkeley James Berkeley Thomas Berkeley Alice Berkeley unknown daughter Berkeley Isabel Berkeley Elizabeth Ferrers, 6th Baroness Ferrers of Groby Partners Elizabeth West Joan Strangways Anne Fiennes