Curt Hofemann, curt_hofemann@@yahoo.com, wrote in a post-em:
[concerning the Norman family of Monfort-sur-Risle]. The first known ancestor of this house is Thurstan of Bastembourg who appears in a ducal charter of 1027 as possessed of land at Pont-Authou, and who, perhaps, also subscribed two charters for Saint-Wandrille which passed to the ducal court at about the same time. This Thurstan has a daughter, with whom the notorious Gere of Echauffour fell in love at first sight while dining with her father and also two sons - William Bertram, who can perhaps be seen in charters for Le Mont-Saint-Michel, and Hugh I of Montfort (some five miles from Pont-Anthou) who perished in the private wars with Walchelin of Ferrieres during the anarchy [of Duke William's minority]. [Ref: William The Conqueror, The Norman Impact Upon England by David C. Douglas 1964 University of California Press, Berkeley & LA, CA p88]