Douglas Richardson, Royal Ancestry: A Study in Colonial and Medieval Families, 2nd edition (Salt Lake City, Utah, 2013), volume IV, page 560

3. MARGARET FITZ EUDES, married (1st) WILLIAM DE MANDEVILLE, Of Great Waltham, High Easter, Pleshey, and Safford Waldon, Essex, Streatley, Berkshire, Quarrendon and Amersham, Buckinghamshire, Edmonton and Enfield, Middlesex, Sawbrideworth, Hertfordshire, Long Compton, Warwickshire, etc., son and heir of Geoffrey de Mandeville, of Great Waltham, High Easter, Pleshey, and Safford Waldon, Essex, Chippenham, Cambridgeshire, Edmonton and Enfield, Middlesex, by his 1st wife, Athelaise. They had one son, Geoffrey [1st Earl of Essex], and one daughter, Beatrice. WILLIAM DE MANDEVILLE probably died before May 1116. His widow, Margaret, married (2nd) OTHUEL FITZ EARL, illegitimate son of Hugh, Earl of Chester [see CHESTER 5 for his ancestry]. They had one son, William. OTHUEL FITZ EARL died in the shipwreck of the White Ship 25 Nov. 1120.

Clutterbuck Hist. & Antiqs. of Hertford 3 (1827): 190-194 (Mandeville-Say ped.), 225-226 (Clare ped.). Munford Analysis of the Domesday Book of the County of Norfolk (1858): 37-38. Round Geoffrey de Mandeville (1892). Devon Notes & Queries 4 (1907): 229-232. C.P. 5 (1926): 113-116 (sub Essex). VCH Huntingdon 3 (1936): 66-69. History 58 (1973): 18-28. VCH Middlesex 5 (1976): 149-154, 224-229. Hollister Monarchy, Magnates, & Institutions in the Anglo-Norman World (1986). VCH Cambridge 10 (2002): 374-379. Tanner, Fams., Friends, & Allies (2004): 302 (Mandeville ped.).