[5] Conrad then marched to Castile, where in Carrión de los Condes the engagement was celebrated and he was knighted in July 1188,[6] making him a servant of his new lord and future father-in-law, King Alfonso VIII.

Berengaria's status as heiress of Castile was based in part on documentation in the treaty and marriage contract,[7][8] which specified that she would inherit the Castilian throne after her father or any childless brothers who may come along.

Pope Celestine III did not want the Staufen dynasty to extend its influence over the Iberian Kingdoms, and when in the autumn of 1191 Berengaria (influenced, no doubt, by third parties such as her grandmother Eleanor of Aquitaine, who was not interested in having a Staufen as a neighbor to her French fiefdoms), requested an annulment of the engagement, the Pope quickly agreed: the betrothal was broken in early 1192 by the Archbishop Gonzalo of Toledo and the Papal Legate Gregor, Cardinal-Deacon of San Angelo, on the grounds that the bride was against the continuation of the engagement.

According to the chronicle of Otto of Sankt Blasien in 1191, Henry VI left the Duchy of Swabia to his brother Conrad after returning from Italy.

According to the chronicle of Burchard of Ursperg, Conrad died in Durlach during a campaign against Berthold V, Duke of Zähringen and was buried at Lorch Abbey.

[18] But the Annals of Konrad von Scheyern recorded specifically that he was bitten in the left nipple by a girl he was attempting to rape; although an increasingly large wound developed, he did not want to be treated and died three days later.

[20] Conrad's burial place, Lorch Abbey, was the necropolis of the Staufen dynasty, donated by his great-grandfather, Frederick I, Duke of Swabia.