JOSCELIN [I] de Courtenay, son of ATHON [Châtelain de Châteaurenard] & his wife --- ([1034]-after 1065). The Historia of Monk Aimon names "Joscelinum de Cortinaco" as son of "Atho filius cuiusdam Gastellarii de Castro-Rainardo"[1678]. Seigneur de Courtenay.
m firstly ([1060]) HILDEGARDE de Château-Landon, daughter of GEOFFROY [II] "Ferréol" Seigneur de Château-Landon, Comte de Gâtinais & his wife Ermengarde d'Anjou . The Historia of Monk Aimon records the marriage of "Joscelinum de Cortinaco" and "filiam comitis Gaufridi Foerole" by whom he had one daughter, who was mother of two sons "Guidonem et Raynardum Comitem de Johegneio"[1679]. She is named in Burke´s Peerage but the primary source on which this is based has not yet been identified[1680].
m secondly ISABELLE de Montlhéry, daughter of GUY "le Grand" Seigneur de Montlhéry & his wife Hodierne de Gometz-la-Ferté. The Historia of Monk Aimon names "Milonem de Brayo et Guidonem Rubeum, Comitissam quoque Reiteste, et Bonam-vecinam de Pontibus, Elizabeth etiam uxorem Joscelini de Corteciniaco, insuper dominam de Puisat, et dominam de S. Galerico" as the children of "Guidonem" and his wife, stating in a later passage that "Elisabeth filiam Milonis de Monte-Letherico" was the second wife of "Joscelinum de Cortinaco"[1681]. It appears chronologically more probable that Isabelle was the daughter of Guy rather than his son Milon, but this is not without doubt. A charter dated 1133 records a donation to the abbey of Saint-Jean de Sens by "Milo de Curteno", adding that his widowed mother had become a nun there and that "frater eius Rainaudus" was buried there[1682], which confirms that Milo was the son of his father´s second marriage. William of Tyre specifies that the mother of Joscelin de Courtenay Count of Edessa was the sister of the mother of Baudouin de Bourg, later Baudouin II King of Jerusalem, according to the testimony of her granddaughter concerning the consanguinity between Amaury I King of Jerusalem and his first wife which provided the basis for the annulment of their marriage in 1162