Isabella was named heir to the throne of Castile by her half brother Henry IV of Castile in the Treaty of bulls of Guisando Ferdinand became the King of Aragon in 1479 . Though their marriage, united the two kingdoms, leading to the beginnings of modern Spain,.They ruled independently and their kingdoms retained their own regional laws and governments for the next few centuries.
• The Kings had a goal of completing the Christian reconquest of the Iberian Peninsula and to conquer the Muslim kingdom of Granada. After 10 years of many battles the Granada War ended in 1492 when the Emir Boabdil surrendered the keys of the Alhambra Palace in Granada to the Castilian soldiers
Ferdinand & Isabella ordered the expulsion from Spain of all Moors and Jews. Conversion to Catholicism was a way of avoiding expulsion, but between 1480 and 1492 hundreds of those who had converted were accused of secretly practising their original religion and arrested, imprisoned, interrogated under torture, and inmany cases burned to death, in both Castile and Aragon The Inquisition was established in the Kingdom of Castile
• They authorized the expedition of Cristopher Colombus which brought knowledge of the Americas to Europe. This lead to an influx of wealth into Spain, filling the coffers of the new state that would prove to be the hegemony of Europe only until 1588.• Isabella died in 1504. Ferdinand remarried Germaine of Foix; he died in 1516.