Arbois de Jubainville names Hilduin [II] and adds that "on peut supposer que cet Hilduin était fils" of Hilduin [II], implying that there is no primary source which confirms that they were father and son.
Comte [de Montdidier]. Seigneur de Ramerupt. Robert II King of France confirmed the donation of "Manasses comes" to Chartres Notre-Dame by charter dated 4 Feb 1031, signed by "…Manasses comitis, Hilduini comitis fratris eius, filiorum eius Manassis et Hilduini, Burcardo de Montemorenciaco, Evrardi filii Hilduini de Britoglio, Amalrici de Monteforti, Milonis de Caprosa…". "…Hilduinus comes et Hilduinus filius eius…" subscribed the charter dated 1032 under which "Odo comes palatinus Francorum regis" founded Epernay abbey. 2
Also called Cte Hilduin III DE MONTDIDIER, Seigneur de Ramerupt.