Two possible parentages of Gauthier [I] have been suggested. Firstly, Edouard de Saint-Phalle suggests that he was Gauthier, son of Raoul [I] Comte [d'Ostrevant]. This possible parentage is also shown in Europäische Stammtafeln. The primary source which suggests that this might be the case has not been identified. The second possibility is that he was the same person as Gauthier Comte de Dreux: the editor of the compilation of Chartres charters suggests that "Walterius…comitis Waleranni filius" (Gauthier Comte de Dreux) inherited "comes Velcassinus" (Vexin) from his father, and "Ambianensis" (Amiens) from "matre autem Eldegarde" (acquiring Dreux from his wife's family). The primary sources on which this information is based have not been identified. However, two facts suggest that this second hypothesis may be correct. Firstly, Gauthier Comte de Dreux is also recorded with a wife named Eva ... Secondly, the castle of Mantes, occupied by the descendants of Gauthier Comte d'Amiens, was near Dreux. One possible resolution of the problem is signposted by Seversmith who states that Gauthier [I] was the son of "Raoul de Gouy" whose wife he names "Eldearde".... the wife of Waleran, supposed father of Gauthier [I] under the second possible case, is named "Eldegardis". If Seversmith is correct, it is possible that Eldegardis married firstly Raoul [I] Comte [d’Ostrevant] and secondly Gauthier Comte de Dreux, and that Gauthier [I] was the son of her first marriage. It should be noted that the charter dated to before 967 under which Eldegardis made a donation for the soul of her husband Waleran, with the consent of "Walterio comite filio meo", does not specify that Gauthier was Waleran’s son, although the omission of an earlier husband from the document would be surprising if that husband had been Gauthier’s father.
"Wauterii comitis, Walterii et Radulfi filiorum eius" subscribed a charter dated 975 under which "Hugo Francorum dux" restored the abbey of Saint-Jean to the abbey of Sainte-Croix d'Orléans.
Comte d'Amiens. A charter of "Hugo…Francorum rex" confirming the privileges of the monastery of Corvey dated 987 is subscribed by "Walteri comitis Ambianensis ac filiorum eius Walteri, Gotfredi, Rodulfi".
The necrology of the abbey of Saint-Germain-des-Prés records the death "XIX Kal Feb" of "Gualterii comitis".
Gauthier married twice, first to Eva... “Aeva” donated “alodum...Fulloni Campum et Mansum Roberti in villa Ludolmis in pago Castrinse” to Saint-Germain-des-Prés, for the souls of “meæ...senioris mei Walterii”, by undated charter. The necrology of the abbey of Sainte-Colombe records the death "XIV Kal Feb" of "Eve comitisse". Gauthier married as his second wife Adela. A list of members of the Cathedral of Paris lists (in order) "…Walterius comes, Adela comitissa…". According to Europäische Stammtafeln, she was Adela d'Anjou, daughter of Foulques [I] "le Roux" Comte d'Anjou & his wife Roscilla [de Loches]. The primary source on which this is based has not been identified; it is possible that it is speculative, based on one of her sons being named Foulques. 1