"Comes Heribertus" names "materque mea Pavia…pater meus Otto, eius genitrix, avia mea Ermengardis" donated property to Notre-Dame de Homblières by charter dated [13 Jan/13 Oct] 1045.
According to Ernest Petit, Ermengardis was the widow of Milon [IV] Comte de Tonnerre. The author highlights a charter of Ermengardis Ctss de Vermandois witnessed by Renaud Comte de Tonnerre. He suggests that Comte Renaud would only have done this if he were the son of Ermengardis, although other explanations must be possible. Settipani points out that Ermengardis is named as the wife of Héribert [IV] in a document of her father-in-law Albert [I] Comte de Vermandois, relating to the abbey of Homblières, dated some time between 982 and the death of Comte Albert (in 987). If the two marriages apply to the same Ermengardis, Comte Héribert must have been her first husband and Comte Milon her second. However, it is not clear that this suggested co-identity is correct, a simpler explanation being that there were two different individuals named Ermengardis. Ernest Petit also suggests that Ermengardis (wife of Comte Milon) was heiress of Bar-sur-Seine, in order to explain how her granddaughter by Comte Milon, Eustachie, transmitted this county to her husband Gauthier de Brienne. He identified the father of Ermengardis as "Renaud Comte de Bar-sur-Seine" based on two charters, which he dated to 992 and 997, which name "Rainardus comes" whom he identifies with Rainard, son of miles Raoul de Bar, who is mentioned in the Chronicle of St Bénigne. There appears to be no other evidence of the existence of this person, and Bouchard points out that the dating of the two charters in question is uncertain. She suggests that it is more likely that "Rainardus" is identified with Renaud Comte de Sens or with "Rainaldus" son of Ermengardis. This of course leaves open the question how Bar-sur-Seine was transmitted to the Tonnerre family. 1