As heiress of Castile, the question of Isabella’s future marriage became a matter of increasing diplomatic activity at home and abroad. Portugal, Aragon, and France each put forward a marriage candidate. Henry seems to have wanted his half sister to marry Afonso V, king of Portugal. As between the Portuguese and Aragonese candidates, she herself,... See more

Isabella demonstrated exceptional political skill even before her marriage to Ferdinand in 1469. She secretly married Ferdinand against the wishes of her half-brother King Henry IV, who had intended her to marry the King of Portugal. This defiance required careful planning and political maneuvering, including obtaining a (likely forged) papal... See more

Ferdinand II, also known as Ferdinand I, Ferdinand III , and Ferdinand V [b] (10 March 1452 – 23 January 1516), called Ferdinand the Catholic , was King of Aragon from 1479 until his death in 1516. As the husband and co-ruler of Queen Isabella I of Castile, he was also King of Castile from 1475 to 1504 (as Ferdinand V ). He reigned jointly with... See more

From her precarious position in the line of succession to the chaotic reign of her half-brother, a series of factors and events not only fueled her ambition but also necessitated the strategic and pivotal union with Ferdinand of Aragon.