|SOME NOTES ON MEDIEVAL ENGLISH GENEALOGY|
Volume 3, page 434 (as modified by volume 14):
He [Sir Piers de Gavaston, Earl of Cornwall (d. 1312)] m., at Berkhamstead, 3 Nov. 1307 [N. Denholm-Young, History and Heraldry, 1965, p. 128 and note 6], Margaret, da. of Gilbert (DE CLARE), EARL OF GLOUCESTER AND HERTFORD, by Joan, da. of Edward I ...
Brad Verity, in February and April 2003, provided further information on the date of the marriage, as follows. A royal account gives the date of the marriage as 1 November 1307 [citing a transcript of P.R.O., E 101/373/15, fo. 22, in Pierre Chaplais, Piers Gaveston - Edward II's adoptive brother p. 34 (1994)]. The date previously given, 3 November, was deduced indirectly by Denholm-Young, from the fact that Piers and Margaret are known from other evidence to have been married before 26 June 1308, in the presence of the king at Berkhampstead. Edward II is known to have been at Berkhampstead only once, 2-3 November 1307, between his accession and June 1308.
[Item last updated: 20 April 2003.]
Volume 3, page 434, note c (as modified in volume 14):
His [Sir Piers de Gavaston's, earl of Cornwall (d. 1312)] eldest da., Joan, was by him destined to have m. Thomas Wake, s. and h. ap. of John [Lord] Wake, but the said Thomas having m. elsewhere, King Edward II, in May 1317, granted her marriage to John, s. and h. ap. of Thomas de Multon, Lord of Egremont, as soon as they should attain to the legal age of marriage. For persuasive evidence that Gaveston had two das., the second, Amy, being b. after 6 Jan. 1312, see J.G. Hunt, Amer. Geneal., vols 35, 1959, pp. 199-6; 37, 1961, pp. 45-7; 40, 1964, p. 25.
Amy's identity continues to be the subject of spirited debate. In contemporary records, she is called Amy de Gavaston several times, and on one occasion Amy the daughter of Peter de Gavaston. But it is clear from the inquisitions post mortem taken after the death of Piers's widow Margaret that, in any case, she was not a legitimate daughter of Piers and Margaret.
[See contributions far too numerous to mention, discussing Amy and her sister Joan.]