Richbod - probably son of Ethelind / Adelindis & Charlemagne

Please see Charlemagne Project for Source Details

Charlemagne's fifth known concubine was Ethelind. Mistress (6): ADELINDIS ---. 806. Einhard names King Charles's concubine "Adallindem", and her son "Theodricum"[89. :[http://fmg.ac/Projects/MedLands/CAROLINGIANS.htm#_Toc240955192

By her he had:

1 Richbod (805–844) , Abbott of Saint-RiquierNote: Cawley thinks Richbod MAY actually have been Charlemagne’s grandson through Fastrada’s daughter, Hiltrude: [RICHBOD ([800/805-killed in battle Angoulême 14 Jun 844). Abbé de Saint-Riquier 840/44. The Annales Bertiniani record that "Richbote abbas…consobrinus regum, nepos…Karoli imperatoris ex filia" was among those killed in 844[151]. It is possible, but not certain, that his mother was Hiltrud, as explained below.] :Hiltrud ([787-after 800, maybe after 814). "Theoderadam et Hiltrudem" are named daughters of King Charles & Fastrada by Einhard[147]. Theodulf's poem Ad Carolum Rege names (in order) "Berta…Chrodtrudh…Gisla…Rothaidh…Hiltrudh, Tetdrada" as daughters of the king[148]. She lived at her father’s court until his death in 814. Wilhelm Kurze appears to have disproved the theory of the alleged marriage of Hiltrud to Eberhard [I] Graf [von Calw], a court official of Emperor Charlemagne[149]. According to Rösch[150], Hiltrud was the mistress (between [799/804]) of Richwin Count of Padua, brother of Richbod Bishop of Trier, who was at the court of Emperor Charlemagne between 792 and 814, and was the mother of an illegitimate son by him. He cites no primary source on which this is based and no reference to this has been found in the sources so far consulted. It is possibly based on onomastic speculation from the use of the first name Richbod.

2 Theodoric (b. 807) Note: Cawley thinks Theoderic was the only son, and Richbod was actually a grandson of Charlemagne through Fastrada’s daughter, Himiltrud THEODERIC [Thierry (807-after 818). Einhard names "Theodricum" as son of King Charles by his concubine "Adallindem"[175]. The birth of "imperatori filius nomine Theodericus" is recorded in 807[176]. He and his half-brothers Drogo and Hugues were brought up in the palace of their half-brother Emperor Louis I after their father died, but after the revolt of Bernard King of Italy in 818 they were forcibly tonsured and "put under free custody into monasteries"[177]. :[http://fmg.ac/Projects/MedLands/CAROLINGIANS.htm#_Toc240955192

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