SIMON de Montfort, son of AMAURY [I] Seigneur de Montfort & his wife Bertrade --- (-25 Sep [1087], bur Epernon[456]). "Ivo de Curba villa" dedicated "ecclesiæ Sanctorum Martyrum Gervasii et Protasii Cheonis" by charter dated to [1048/61], witnessed by “...Amalricus de Sparnoto, Simon et Mainerius filii eius...”[457]. "Amalricus miles" founded the priory of Saint-Thomas d’Epernon, with the consent of "conjugis mee…Bertredis…et filiorum meorum…Simonis…atque Mainerii", by charter dated [11 Apr 1052/Jul 1053][458]. He succeeded his father as Seigneur de Montfort and completed the construction of the castle known as Montfort-l'Amaury which was started by his father[459]. "…Simon de Monte forti…" witnessed the charter dated 29 May 1067 under which Philippe I King of France confirmed the possessions of Saint-Martin-des-Champs[460]. Orderic Vitalis records the death of “Simon de Monteforti, gener Ricardi comitis Ebroicensium”, dated to 1087 from the context[461]. "Mainerium, fratrem Symonis de Monte Forti" donated property, with the consent of "Simone fratre eius comiteque Belli Montis Ivonis", by charter dated to before 1091, which also names "domnus Simon, filio suo Amalrico"[462].
m firstly ISABELLE de Broyes dame de Nogent-le-Roi, daughter of HUGUES [I] "Bardoul" de Broyes & his [first wife ---]. Her parentage and marriage are confirmed by a charter dated 1160 under which Louis VII King of France confirmed donations to the abbey of Colombs near Nogent, including donations made by "Hugo…Bardulfus…et Simon de Monteforti gener eius et successor"[463]. The primary source which confirms her name has not yet been identified. The Historia of Monk Aimon records that "dominam de Novigento" married the lord of "Montifortem et Sparnomum", although the passage is confused as it appears to refer to the paternal grandparents of Simon, husband of Isabelle[464].
m secondly ---. The primary source which confirms her marriage has not yet been identified.
m thirdly AGNES d'Evreux, daughter of RICHARD Comte d'Evreux [Normandie] & his wife Godechildis ---. Orderic Vitalis records that “Radulfus...de Conchis filius Rogerii de Toenia” kidnapped “Agnetem uterinam sororem suam, Ricardi Ebroicensium comitis filiam” by night and married her to “Simoni de Monteforti”, who in exchange granted “filiam eiusdem Simonis...Isabel” to Raoul[465]. In other passages he names her and specifies that she was the daughter of Richard and sister of Guillaume[466].