Gwladys ferch Dafydd Gam Welsh noblewoman (1380–1401) Parents Gwenllian ferch Gwilym ap Hywel Grach ap Gwilym ap Hywel Dafydd Gam Children William Herbert, 1st Earl of Pembroke Elizabeth Vaughan Elizabeth Herbert Roger Vaughan of Tretower Richard Herbert Watkyn Vaughan Thomas ap Roger Vaughan Margred Herbert, of Raglan Siblings Morgan ap Dafydd Gam ap Llywelyn ap Hywel Fychan Partners Roger Vaughan of Bredwardine William ap Thomas