Isabella I of Castile

Isabella I (Spanish: Isabel I; 22 April 1451 – 26 November 1504), also called Isabella the Catholic (Spanish: Isabel la Católica), was Queen of Castile and León from 1474 until her death in 1504. She was also Queen of Aragon from 1479 until her death as the wife of King Ferdinand II. Reigning together over a dynastically unified Spain, Isabella and Ferdinand are known as the Catholic Monarchs. Her reign marked the end of Reconquista and also the start of Spanish Empire and dominance of Spain over European politics for the next century.

Isabella's marriage to Ferdinand of Aragon in 1469 created the basis of the de facto unification of Spain. With Ferdinand's help, she won the War of the Castilian Succession, securing her position as Queen of Castille. Isabella reorganized the governmental system, brought the crime rate down, and unburdened the kingdom of the debt which her half-brother King Henry IV had left behind. Her reforms and those she made with her husband had an influence that extended well beyond the borders of their united kingdoms.

Isabella and Ferdinand are known for being the first monarchs to be referred to as the queen and king of Spain, respectively. Their actions included completion of the Reconquista, the Alhambra Decree which ordered the mass expulsion of Jews from Spain, initiating the Spanish Inquisition, financing Christopher Columbus's 1492 voyage to the New World, and establishing the Spanish Empire, making Spain a major power in Europe and the world and ultimately ushering in the Spanish Golden Age.

Together with her husband, Isabella was granted the title of "Catholic Monarch" by Pope Alexander VI, a Spaniard. Her sainthood cause was opened in 1958, and in 1974, after her death when she could not reject the offer, she was granted the title of Servant of God in the Catholic Church.

Isabella was born in Madrigal de las Altas Torres to King John II of Castile and his second wife, Isabella of Portugal, on 22 April 1451 (Maundy Thursday). At the time of Isabella's birth, she was second in line to the throne after her older half-brother Henry. Henry was 26 at that time and married, but childless. Isabella's younger brother Alfonso was born two years later on 17 November 1453, demoting her position to third in line. When her father died in 1454, her half-brother ascended to the throne as King Henry IV. Isabella and her brother Alfonso were left in King Henry's care. Isabella, Alfonso, and their mother then moved to Arévalo.

This is the letter that King John II sent to the city of Segovia to announce the birth:

I let you know that by the grace of Our Lord, this past Thursday, Queen Doña Isabel, my very dear and beloved wife, gave birth to a princess. I share this news so that you may give many thanks to God.

These were times of turmoil for Isabella. The living conditions at the castle in Arévalo were poor, and they suffered from a shortage of money. Although her father arranged in his will for his children to be financially well taken care of, Henry did not comply with their father's wishes, either from a desire to keep his half-siblings restricted or from ineptitude.^{[page needed]} Even though her living conditions were difficult, Isabella was instructed in lessons of practical piety and in a deep reverence for religion under the supervision of her mother.