Dear Newsgroup ~
Complete Peerage 4 (1916): 132–133 (sub Deiville) has a good account of Sir John Deiville, Knt., of Thornton Bridge (in Brafferton), Adlingfleet, Cundall, Kilburn, Leckby (in Cundall), and Thornton-on-the-Hill (in Coxwold), Yorkshire, and Egmanton, Nottinghamshire. He was born say 1276 (still a minor in 1295), and died 1325-6.
Regarding his first marriage, the following information is provided:
"He married, 1stly, Agnes." END OF QUOTE.
No documentation is given in this account for this marriage. However, on page 133, footnote g, under the account of Sir John Deiville's son and heir, Sir Robert Deiville, specific evidence is cited that Sir Robert Deiville was the son of Sir John Deiville [died 1325-6], by his wife, Agnes. Here are those comments:
"It is stated (De Banco, Easter, 5 Edw. III, m. 261) that he [Robert] was son of John Deyville, of Egmanton, son of John Deyville of Egmanton, by Maud his wife. Also (Idem, Easter, 6 Edw. III, m. 320) that he [Robert] was son of John Deyville of Adlingfleet, by Agnes his wife." END OF QUOTE.
The first lawsuit cited by Complete Peerage is a Common Pleas lawsuit dated 1331, which lawsuit identifies John de Eyvill [died c.1291] and his wife, Maud, as the parents of John de Eyvill [died 1325–6], which younger John in turn is identified as the father of Robert de Eyvill, of Egmanton, Nottinghamshire, living in 1331. Reference: Court of Common Pleas, CP40/285, image 535f, available at
http://aalt.law.uh.edu/AALT2/E3/CP40no285/aCP40no285fronts/IMG_0535.htm.
The second lawsuit cited by Complete Peerage is a Common Pleas lawsuit dated dated 1332, which identifies John de Eyvill [died 1325–6] and his wife, Agnes, as the parents of Robert de Eyvill, of Adlingfleet, Yorkshire, living in 1332. Reference: Court of Common Pleas, CP40/290, image 647f (available at
http://aalt.law.uh.edu/AALT1/E3/CP40no290/aCP40no290fronts/IMG_0647.htm).
The second lawsuit confirms that Sir John Deiville's first wife was Agnes and that she was the mother of his son and heir, Robert, just as stated by Complete Peerage. Due to chronological considerations, I believe Agnes was also the mother of Sir John Deiville's older two daughters, ELizabeth (wife of Alexander de Leeds, Knt.) and Margaret.
Complete Peerage makes no attempt to identify Agnes Deiville. However, recently I came across a pedigree of the Harcourt family published in Lipscomb, History & Antiquities of Buckingham 4 (1847): 589–592 (Harcourt ped.). In this pedigree, the author assigns Agnes, wife of Sir John Deyvilles, Knt. as the daughter of Sir Richard de Harcourt, of Stanton Harcourt, Oxfordshire [died 1293], by his 1st wife, Margaret, daughter and co-heiress of John [de] Beke, Lord Beke.
The Harcourt pedigree can be found at the following weblink:
https://play.google.com/books/reader?id=mXkgAQAAMAAJ&printsec=frontcover&output=reader&hl=en&pg=GBS.PA590
While Mr. Lipscomb doesn't provide his source for the identification of Agnes Deiville, I'm reasonably confident that he is correct. As far as I know, Mr. Lipscomb had no knowledge of the 1332 Common Pleas lawsuit which proves that Sir John Deyville's wife was named Agnes. As such, I assume that he must have used yet another source which placed Agnes, wife of Sir John Deyville as the daughter of Sir Richard de Harcourt.
For interest's sake, the extended ancestry of Agnes de Harcourt may be viewed at the following weblink.
http://www.genealogics.org/verticalchart.php?personID=I00029015&tree=LEO&parentset=0&display=vertical&generations=7
A review of Agnes de Harcourt's extended ancestry finds that she descends from King Henry I of England, King Malcolm III of Scotland, Isabel de Vermandois (twice), King Henry I of France, Alice of Normandy (sister of King William the Conqueror) (twice), and the ever popular Milicent de Rethel.
Best always, Douglas Richardson, Salt Lake City, Utah