When Alfonso was around seven years of age the two children were moved to Henry's court at Madrid and were placed in Queen Joan's household.

Henry agreed to the compromise with the stipulation that Alfonso someday marry Joanna, to ensure that they both would one day receive the crown.

On 5 June 1465, the nobles in league against him conducted a ceremonial deposition-in-effigy of Henry outside the city of Avila and crowned Alfonso as a rival king.

[3] In 2006, during the restoration of the charterhouse, the General Directorate of Cultural Heritage and Assets of the Junta de Castilla y León decided to carry out an anthropological study on the tombs.

[4] In 2013 a further study based on these results was published by the University of Leon, theorising that Alfonso was poisoned, as his symptoms did not align with those of Bubonic plague, and his remains show no trace of the bacteria Yersinia pestis.

Shortly thereafter, she declined, and after a negotiation at Toros de Guisando, in which she and her allies received most of what they desired, Henry was convinced to exclude Joanna la Beltraneja from the succession, and to recognize Isabella as his official heir.