William de Ferrers, 5th Earl of Derby
…Mortimer, younger son of Ralph de Mortimer; Eleanor de Ferrers (died 16 October 1274) married (1) William de Vaux, (2) in about 1252 (as his 3rd wife) Roger de Quincy, 2nd Earl of Winchester, and (3) in about 1265 Roger de Leybourne. He married (2nd) in 1238 Margaret or Margery de Quincy (c. 1218 - 12 March 1280), daughter and heiress of…