Even before 1180, he had betrothed his daughter to Henry, the eldest son of Henry the Lion, in order to defuse the re-emerging conflict between the Houses of Hohenstaufen and Welf. Her father avoided definitive statements on her bethrothal, because he preferred a marriage with the French king, but he did not want to offend Henry, whom Agnes revered fanatically.
Agnes" father, Conrad, Count Palatine of the Rhine and the half-brother of Emperor Frederick Barbarossa, was a politician, who aimed for peace and reconciliation in the kingdom. When the young Henry the Welf heard of this plan, he contacted Agnes" parents. Henry VI felt betrayed and demanded that Conrad immediately annul the marriage.
Conrad, however, dropped his initial resistance to the marriage and, seeing as it had already been blessed in Church, chose to convince Henry VI of the domestic political benefits of this marriage.
Conrad"s sons had died young and Henry VI could assure the succession of the Palatinate of the Rhine by enfeoffing Henry the Welf. Additionally, Conrad and Agnes convinced the emperor to pardon Henry the Lion, who had been outlawed by Barbarossa.
The reconciliation between Henry VI and Henry the Lion was held in March 1194 at Tilleda Castle. Henry VI wanted to settle the conflict with the House of Welf, so he could have peace in the Holy Roman Empire and enforce the claim on Sicily he had after the death of Tancred of Lecce on 20 February 1194.
Henry, was Count Palatine of the Rhine from 1212 to 1214
Irmengard (1200–1260), married Herman V, Margrave of Baden-Baden
Agnes (1201–1267), married Duke Otto II of Bavaria.
Agnes and Otto are the ancestors of the House of Wittelsbach in Bavaria and the Palatinate. Her daughter Elisabeth was the mother of Conradin. Her son Louis was the father of Emperor Louis IV.
In Christian Dietrich Grabbe"s drama entitled Henry VI of 1830, she is depicted as a carefree but resolute girl, who went before the Imperial Diet to marry the man she loved.
She fights for his love and happiness and brings about the reconciliation of the Welf and the Hohenstaufen on the deathbed of her father-in-law, Henry the Lion.
The opera Agnes of Hohenstaufen by the Italian composer Gaspare Spontini had its premiere on 12 June 1829 at the Royal Opera in Berlin.
During the Romanticism period in the 19th century, the picture of Agnes of Hohenstaufen was coloured more brightly.
