Isabella the Catholic, Queen of Castile

ISABELLA THE CATHOLIC, Queen of Castile. -
Born 22 Apr. 1451 at Madrigal de las Altas Torres,
died 26 Nov. 1504 at Medina del Campo.

Daughter of John II of Castile and of Isabella of
Portugal, in 1469 at Valladolid she married Ferdinand of Aragon. On the death of her brother Henry IV, who reigned in
Castile, I. was crowned queen in 1474. As soon as she ascended the throne she found herself involved in a war against
Alfonso V of Portugal, who supported the succession to the Kingdom of Castile of her niece Joanna la
Beltraneja, illegitimate daughter of the wife of Henry IV,
Joanna of Portugal. By the treaty of Trujillo (1479)
I. obtained from Alfonso V the renunciation of his niece's supposed rights
over Castile. When John II of Aragon died in the same
year, Ferdinand succeeded him in the Kingdom and the union of the two crowns of Castile and Aragon opened the way to the unification of Spain, which
I. and Ferdinand carried out in part during their common reign, after a long war, with the conquest of the
Muslim Kingdom of Granada (1492). I. also strengthened
internally the royal authority, greatly decayed during the reign
of Henry IV. Another fundamental concern of I.
was the reform of the regular and secular clergy and the realization of the religious unity of the territories subject to
her authority. New impetus was given to the inquisition and
the assimilation of the Moors and the Jews was proceeded with, the latter being obliged either to be baptized or to leave Spain within four months (edict of 31 March 1492).