Guillaume I de Poitiers, I. comte de Valentinois

Alias: Guillaume de Peytieux , Guillaume Le Poitevin Titles: comte de Valentinois (1er) Officier à la cour impériale, officie vero Valentinus comes (1159-1161), Valentinensium comiti (1165)

• Notes about sorces for his ancestry...
  • Research by Jules Chevalier. This is a common source, and suggests Adhémar I de Poitiers and Véronique de Marsanne as parents. This is based on an undated charter concerning the abbey of Leoncel. However, this charter could apply to Adhémar de Poitiers-Valentinois, married to Philippa de Fay at a later date.
    • This theory, as well as others, seem at odds with onomastics.
  • Michèle Blois offers a far more compelling theory.
    • Central to all theories is the existence of two brothers, Guillaume and Eustache, in relationship to Valence. In 1107, Eustache de Forez becomes comte-évêque of Valence. In the same year, the county of Forez is acquired by Guy d'Albon from Eustache's brother, Guillaume 'le Jeune' de Forez. Forez is part of the larger Poitou, which can explain the adoption of the 'surname' de Poitiers. This would explain also the addition of "Valentinois", derived from "de Valence". Given the attachment to Valence, and the chronology, it seems most plausible that the first Count of Poitier-Valentinois is indeed the son of Eustache de Forez.
  • Please don't hesitate to open a debate about these theories!