Adelaide and Frederick's marriage was not successful, however. According to some later sources, this was because Adelaide committed adultery.[6][7][8] Adelaide rarely made public appearances and was not present for Frederick's election as the successor of his paternal uncle, Conrad III, on 4 March 1152, nor for his coronation as King of Germany at Aachen Cathedral five days later.
Adelaide was Frederick's queen consort, but the couple remained childless.[9] In 1153 Frederick petitioned Pope Eugene III for an annulment. The separation was granted and confirmed by the Bishop of Constance in March 1153; the justification given on grounds of consanguinity.[6] Frederick immediately began to court the Byzantine princess Maria Komnena, though to no avail.
No longer a queen, Adelaide, apparently unhampered by her former husband, soon after entered into a morganatic marriage with Dietho of Ravensburg, a ministerialis in the service of Duke Welf VI.[4] The marriage produced several children. Dietho died about 1187; Adelaide died shortly afterwards at the Premonstratensian abbey of Weissenau near Ravensburg.
"Annales Palidenses, a. 1155. 1156.", Monumenta Germaniae Historica Inde Ab Anno Christi Quingentesimo Usque Ad Annum Millesimum et Quingentesimum. (in Latin), Hannover: Impensis Bibliopolii Aulici Hahniani: 89, 1826, ISSN0343-2157, OCLC12302731
Bedürftig, Friedemann (2006). Die Staufer: ein Lexikon [The Staufer: an encyclopedia] (in German). Darmstadt: Primus. ISBN3-89678-288-6. OCLC70063808.
Pertz, Georg Heinrich, ed. (1874). Monumenta Germaniae Historica: Scriptorvm (in Latin). Vol. 23. Stuttgart: Societatis Aperiendis Fontibvs Rervm Germanicarvm Medii Aevi. OCLC164582170.
Weller, Tobias (2004). Die Heiratspolitik des deutschen Hochadels im 12. Jahrhundert [The Marriage Policy of the German High Nobility in the 12th Century] (in German). Köln: Böhlau. ISBN3-412-11104-X. OCLC57388984.