Isabella I of Spain, born in 1451, was the Queen of Castile and León. She is best known for her marriage to Ferdinand II of Aragon, which united two of the largest kingdoms in Spain. Together, they completed the Reconquista by capturing Granada in 1492, marking the end of Muslim rule in the Iberian Peninsula. In addition to her military achievements, Isabella sponsored Christopher Columbus on his 1492 voyage, leading to the discovery of the Americas. Her reign is often associated with the establishment of a unified Spanish state and the beginning of Spain's global exploration and colonization efforts.