HILDEGARD (758-Thionville, Moselle 30 Apr 783, bur Metz, église abbatiale de Saint-Arnoul). Einhard refers to Hildegard as "de gente Suavorum"[327]. Thegan's Vita Hludowici Imperatoris names her "Hildigardam quæ erat de cognatione Gotefridi ducis Alamannorum" and specifies that she was the daughter of Imma[328]. The Annales Laurissenses record the death "783 pridie Kal Mai" of "Hildegardis regina" and her burial "iuxta urbem Mettensem in basilica apostolorum et beati Arnulfi"[329]. She died from the after effects of childbirth, according to the epitaph of her daughter Hildegarde[330]. Paulus Diaconus wrote an epitaph to "Hildegardis regina"[331]. m (Aix-la-Chapelle 771 before 30 Apr) as his second wife, CHARLES I King of the Franks, son of PEPIN "le Bref" King of the Franks & his wife Bertrada [Berta] "au Grand Pied" (near Aix-la-Chapelle 2 Apr 748-Aix-la-Chapelle 28 Jan 814, bur Aix-la-Chapelle, Chapelle Sainte-Marie). He was crowned CHARLES I "Charlemagne" Emperor of the Romans in 800.
http://fmg.ac/Projects/MedLands/SWABIAN%20NOBILITY.htm#Hildegardisdied783
Hildegarde de Vintzgau (v. 758 - † 30 avril 783 Thionville), fille de Gérold Ier de Vintzgau et Emma d'Alémanie.
Elle épouse Charlemagne en 771 et lui donne neuf enfants. Elle meurt en mettant son dernier enfant au monde, et est inhumée en l'église abbatiale Saint-Arnould à Metz.
http://fr.wikipedia.org/wiki/Hildegarde_de_Vintzgau