Mathilde De Sexfontaines 
General Notes
SOURCES: LDS FHL Ancestal File # (familysearch.org)
"Ancestors/Descendants of Royal Lines" (Contributors: Manuel Abranches de Soveral, Reynaud de Paysac, F.L. Jacquier <Genealogy of Lewis Carroll, Justin Swanstrom, The Royal Families of England Scotland & Wales by Burkes Peerage; Debrett's Peerage & Baronage; Table of descendants French Canadian Genealogical Society; Families of Monfort-sur-Risle & Bertrand de Bricquebec; The Dukes of Normandy, XXXXI, Paul Leportier, Claude Barret; Irish Catholic Encyclopedia>, H.R. Moser <Burke Peerage>, L. Orlandini, O.Guionneau, L.B. de Rouge, E. Polti, A.Terlinden <Genealogy of the existing British Peerage, 1842>, L. Gustavsson, C. Cheneaux, E. Lodge, S. Bontron <Brian Tompsett>, R. Dewkinandan, H. de la Villarmois, C. Donadello; Scevole de Livonniere, H. de la Villarmois, I. Flatmoen, G. Kepklian)... http://geneastar.org.
‌Mathilde De and Simon IV De were married in a religious ceremony in 1269. They had two daughters named Jeanne De and Laure De.