Madelgard, concubine of Charlemagne. Her ancestry is unknown. She might have been a sister of Duke Madelgaud, who was perhaps count of Beauvais.

Madelgard, Charlemagne's 5th partner & 2nd concubine

His second known concubine was Madelgard. [http://en.wikipedia.org/wiki/Charlemagne
Note: Wikipedia seems possibly to conflate what Charles Cawley sees as 2 mistresses and their respective daughters Ruodhaid / Chrothias / Rotaide / Ruodhaidem / Rothildis / Rouhaut, in a manner that seems worth considering. Although Cawley designates an unknown Mistress 2 before Madelgard - who he sees as Mistress 3, he lists the daughters of both mistresses as being born in 784. Despite this, he specifies that Madelgard’s daughter was Abess of Faremoutiers, - although Wikipedia sees her as being born in 775. The Wikipedia sources for this date weren’t apparent, but Cawley’s use of Theodulf's poem Ad Carolum Rege naming the daughters (supposedly in order) provides another form of data: "Berta…Chrodtrudh…Gisla…Rothaidh…Hiltrudh, Tetdrada" [156] As both Wikipedia & Cawley agree that Gisela was born 781, Hiltrude in 787 & Theodrata 785 (so much for correct order), this places one Rothaide - between 781 & 787, so I Sharon am deferring to Cawley on the date, but going with Wikipedia in conflating the women whose children he has born in the same year, with names that are sufficiently similar as to be synonymous. Compare: Cawley: NN Mistress 2's daughter: 784. Ruodhaidem CHROTHAIS [Rota%C3%AFde]. Cawley: Madelgard, Mistress 3's daughter: 784. ROTHILDIS [Rouhaut]. Abbess. Wikipedia: Madelgard's daughter:775.Ruodhaid. Abbess.

Mistress (3): [MADELGARD] ---. Settipani names Madelgardis as the mistress of King Charles, and mother of Rothildis abbess of Faremoutiers[86]. However, he cites no primary source on which this is based, apart from a reference to an early 9th century list of nuns at Faremoutiers which includes the name. No reference has been found to her in any of the sources so far consulted. http://fmg.ac/Projects/MedLands/CAROLINGIANS.htm#_Toc240955192] Mistress (2):Einhard refers to "Ruodhaidem" as the daughter of King Charles and an unnamed concubine[85]. http://fmg.ac/Projects/MedLands/CAROLINGIANS.htm#_Toc240955192]

By her he had:

5.1 Ruodhaid (775–810), Abbess of Faremoutiers [http://en.wikipedia.org/wiki/Charlemagne] ROTHILDIS [Rouhaut] ([784]-24 Mar 852). Abbess at Faremoutiers from before Oct 840[157]. Her parentage is proved by the necrology of the abbey of Saint-Germain-des-Prés which records the death "XI Kal Apr" of "Rothildis abbatisse et monache filia regis magni Karoli"[158]. The necrology of the abbey of Saint-Denis records the death "XI Kal Mar" of "Rotildis abbatissa"[159]. [http://fmg.ac/Projects/MedLands/CAROLINGIANS.htm#_Toc240955192] CHROTHAIS [Rota%C3%AFde] ([784]-after 800, maybe after 814). "Ruodhaidem" is named daughter of King Charles and an unnamed concubine by Einhard[155]. Theodulf's poem Ad Carolum Rege names (in order) "Berta…Chrodtrudh…Gisla…Rothaidh…Hiltrudh, Tetdrada" as daughters of the king[156]. :[http://fmg.ac/Projects/MedLands/CAROLINGIANS.htm#_Toc240955192]

Please see Charlemagne Project for Source Details

From Wikipaedia: Marriages and heirs of Charlemagne Charlemagne had twenty children over the course of his life with eight of his ten known wives or concubines. Nonetheless, he only had four legitimate grandsons, the four sons of his third son, Louis. In addition, he had a grandson (Bernard of Italy, the only son of his third son, Pippin of Italy), who was born illegitimate but included in the line of inheritance. So, despite twenty children, the claimants to his inheritance were few.

1. His first relationship was with Himiltrude. The nature of this relationship is variously described as concubinage, a legal marriage, or a Friedelehe.[35] (Charlemagne put her aside when he married Desiderata.) The union with Himiltrude produced two children: - Amaudru, a daughter[36] - Pippin the Hunchback (ca. 769–811)

2. After her, his first wife was Desiderata, daughter of Desiderius, king of the Lombards; married in 770, annulled in 771.

3. His second wife was Hildegard (757 or 758–783), married 771, died 783. By her he had nine children: - Charles the Younger (ca. 772–4 December 811), Duke of Maine, and crowned King of the Franks on 25 December 800 - Carloman, renamed Pippin (April 777–8 July 810), King of Italy - Adalhaid (774), who was born whilst her parents were on campaign in Italy. She was sent back to Francia, but died before reaching Lyons - Rotrude (or Hruodrud) (775–6 June 810) - Louis (778–20 June 840), twin of Lothair, King of Aquitaine since 781, crowned Holy Roman Emperor in 813, senior Emperor from 814 - Lothair (778–6 February 779/780), twin of Louis, he died in infancy[37] - Bertha (779-826) - Gisela (781-808) - Hildegarde (782-783)

4. His third wife was Fastrada, married 784, died 794. By her he had: - Theodrada (b.784), abbess of Argenteuil - Hiltrude (b.787)

5. His fourth wife was Luitgard, married 794, died childless.

Concubinages and illegitimate children: 6. His first known concubine was Gersuinda. By her he had: - Adaltrude (b.774)

7. His second known concubine was Madelgard. By her he had: - Ruodhaid (775–810), abbess of Faremoutiers

8. His third known concubine was Amaltrud of Vienne. By her he had: - Alpaida (b.794)

9. His fourth known concubine was Regina. By her he had: - Drogo (801–855), Bishop of Metz from 823 and abbot of Luxeuil Abbey - Hugh (802–844), archchancellor of the Empire

10. His fifth known concubine was Ethelind. By her he had: - Richbod (805–844), Abbott of Saint-Riquier - Theodoric (b. 807)

http://en.wikipedia.org/wiki/Charlemagne