|SOME NOTES ON MEDIEVAL ENGLISH GENEALOGY|
Volume 6, page 486:
He [William Heron or Heyrun (d. 1379)] m. Isabel.(i)
Northumberland Feet of Fines, 181/12. Her parentage is not known, but it appears from De Banco R., 411, m. 218, that she was aunt and coh. of William de Grey, dead by 1362. Margaret, wife of Sir John de Eure, was another aunt and coh., and other coheirs were Sir John Salvayn and Sir William de Felton. The claimant was Sir Thomas de Grey in respect of the manor of Hundburton (Catton), near Stamford Bridge, Yorks.
Rosie Bevan, in April 2002, produced evidence indicating that Isabel, Margaret and the mothers of Sir John Salvayn and Sir William de Felton were daughters of Sir Thomas de Grey of Heton (d. by 1343/4). If this is correct the William, whose heirs they were, would appear to have been a son of Thomas's son and heir, Thomas (d. 1369) - a father being unable to inherit from a son who died in his lifetime.
The description of the de Banco plea above is rather inaccurate. The lands concerned were the manors of Hundburton (now known as Burton Fields) and Wilberfoss. Sir Thomas de Gray called the heirs of Sir William Gray to warrant against Sir Thomas Ughtred, who had claimed against him [P.R.O. CP 40/411, m. 218].
[This problem was also discussed by Mike Welch and Douglas Richardson.]