The Infanta Berenguela, eldest daughter and heir of King Alfonso VIII of Castile, was married (by contract) to Duke Conrad II of Swabia, an important magnate from the Holy Roman Empire and younger brother of the reigning Emperor Henry VI (81).
The treaty is made even more important because of the events it preceded: with the surety of the treaty, Alfonso VIII of Castile pressed forward to his (unforeseeable) defeat at Alarcos in the following year (88).
A letter written to the Cardinal Gregory by Celestine Ill, from late May 1196 suggests that the Cardinal had been quite busy, although much of the letter was a repetition of earlier letters from March written to Sancho VII of Navarra, Alfonso VIII of Castile, and Pedro II of the Crown of Aragon (116).
(4) Coincidentally, this duchy was a part of the dowry that Alfonso's great-grandmother, Eleanor (1162-1214), daughter of the English King Henry II (1133-89) and Eleanor of Aquitaine (c.1122-1204), brought with her when she married King Alfonso VIII of Castile
Rose Walker contributes chapter 4, 'Leonor of England and Eleanor of Castile: Anglo-Iberian Marriage and Cultural Exchange in the Twelfth and Thirteenth Centuries', where she compares two similar Anglo-Iberian marriages: that of Henry II's daughter, Leonor, to Alfonso VIII of Castile
with that of Eleanor of Castile and Edward, Henry III's son.
responsibility for advising Alfonso VIII of Castile
to ask his noblemen
Ferdinand II of Leon had increasingly allied himself with the Almohads against the growing threats to his kingdom from Portugal and Castile and Alfonso IX, deeply embittered by his early humiliation at the hands of Alfonso VIII of Castile, sided with al-Mansur after the Castilian defeat at Alarcos (11).
Although Innocent was frustrated during a number of years by the continuation of the marriage (a situation for which, from the reports he received, he actually considered Alfonso VIII of Castile primarily to blame), it should be remembered that it was the pope's consistent opposition which ultimately led to the separation of Alfonso IX and Berenguela (by then, of course with four children, including the future Ferdinand III), a separation which caused further conflict over Berenguela's dowry (41).