The following information is provided in a post-em by Curt Hofemann, curt_hofemann@@yahoo.com:
Note: Curt's sources may be right; Turton has William as son of Robert & Sibyl de Valognes, which would make him much younger than I have him. ##check ancestry.
This needs more research. I show this William & Nicholas who married Gunnora d'Aubigny as brothers not father & son. Source: "English Baronies, A Study of Their Origin and Descent 1086-1327" by Ivor John Sanders, 1960, Clarendon Press, Oxford.
I do note that Turton & Watney show them as father & son, but as far as credibility/reliability, I choose Sanders - my opinion only.
Baron of Cottingham [Ref: Sanders p37]
Research note: Turton also mistakenly makes Bertha (niece of Ranulph) and William de Stuteville ancestors of the later Stutevilles. [Turton, W H *The Plantagenet Ancestry* (London, 1928 [Reprint by GPC 1993]) 123, 106] [Ref: Richard Borthwick <rgbor@@cyllene.uwa.edu.au> message to soc.genealogy.medieval 1 Sep 1998]
Lord de Stuteville, who married Bertha de Glanville, probably gave the Church of Dedham, in the Hundred of Lexden, Essex, to Butley Priory, founded by Lord Ranulph de Glanville, his wife's uncle. This gift continued to be held by the Prior of Butley until the dissolution. The Stutevilles were a great baronial house; they came in at the Conquest, and received large possessions in England. Robert de Stuteville fought against Henry I. at Tenerchebrai, and was taken prisoner. [fn 86] The family was officially connected with the Glanvilles in the North, and a close friendship appears to have existed between the two houses. One of them married a daughter of the De Valoins, which probably cemented still closer the families. William de Stuteville, of Gressenhall, Norfolk (a baron of the realm), espoused Margaret, daughter and heiress of Hugh de Say, of Richard's Castle, from whose descendants it passed by a female to the Talbots. The arms of Stuteville and Glanville are still to be seen at Richard's Castle. Bertha de Stuteville (nee Glanville) brought with her, on her marriage, the lordships of Braham and Leyburn. She had two sons, Robert, ob. s.p.; and Nicholas, who succeeded his brother (7th John). He married Gunnora, daughter of Hugh de Gurney, and relict of Robert de Gant, and by her had issue Nicholas de Stuteville, who died, 17th Henry III., leaving two daughters and coheiresses - Johanna, who married Hugh de Wake; and Margaret, the wife of William Mastoc. [fn 87] In the year 1207, Robert, son and heir of Ralph, Lord of Middleham, who married Helwisa de Glanville, daughter of Lord Ranulph de Glanville, the Chief Justiciary, gave 200 marks fine to the King for livery of the property belonging to Bertha, niece of Lord Banulph de Glanville, and wife of William de Stuteville, lying in Leyburn and Barham. [fn 86] Banks says that the family of Skipwiths descend from a younger son of this personage [Ref: Records of the Anglo-Norman House of Glanville from A.D. 1050 to 1880, by Wm. Urmston S. Glanville-Richard, Esq. (London: Mitchell and Hughes 1882) http://ourworld.compuserve.com/homepages/jglanville/roanhg5.htm]
Caveat Emptor, this last ref. differs from my research in places too.
Regards,
Curt