Guillaume I De+ Thiers 
Guillaume I De+ was born about 0978. Guillaume I De+'s father is Guy II De+ Thiers. His paternal grandfather is Etienne De+ Thiers. He is an only child.General Notes
SOURCES: LDS FHL Ancestal File # (familysearch.org)
"Ancestors/Descendants of Royal Lines" (Contributors: F. L. Jacquier {History of Charlemagne" by Christian Settipani}; L. Orlandini, Manuel Abranches de Soveral, Reynaud de Paysac, F.L. J P de Palmas {Aurejac et Tournemire; Frankish line; The Complete Peerage}, 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}, A. Brabant {"Dynastie Montmorency, Michel d'Herbigny}, Paul Leportier, Claude Barret, H.R. Moser {Burke Peerage}, O.Guionneau, L.B. de Rouge, E. Polti, N. Danican {Britain's Royal Families; Buthlaw, Succession of Strathclyde, the Armorial 1961-62} 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, P. Ract Madoux {History of Morhange; Leon Maujean; Annuaire de Lorraine, 1926; La Galissonniere: Elections d'Arques et Rouen}, Jean de Villoutreys {ref: Georges Poull}, E. Wilkerson-Theaux {Laura Little}, O. Auffray, A. Brabant {Genealogy of Chauvigny of Blot from "Chanoine Prevost Archiviste du Diocese de Troyes Union Typographique Domois Cote-d'Or 1925}.... http://geneastar.org.
They have a son named Etienne De+.