Ferdinand V and Isabella I of Spain

Christopher Columbus presenting to Queen Isabella and king Ferdinand
Christopher Columbus presenting to Queen Isabella and king Ferdinand

Ferdinand (1452–1516) and Isabella (1451–1504) united Castile and Aragon creating modern Spain under a dual monarchy, initiated the Spanish Inquisition, conquered Granada, expelled the Moors and the Jews who would not convert to Christianity, funded Christopher Columbus, and established royal authority.

Ferdinand was born at Sos, Aragon, on March 19, 1452, as the son of John II of Aragon and Navarre (1397–1479) and Juana Enriquez, his second wife. As heir to the throne of Aragon, Ferdinand became king of Sicily in 1468. He was skillful, ruthless, ambitious, self-centered, and political in all his endeavors. Ferdinand was often deceitful in his agreements, repudiating treaties and other agreements soon after they were signed.

Ferdinand married his equally ambitious, pious, but wiser cousin Isabella of Castile and León. She was born at Madrigal de las Torres in Castile on April 22, 1451, the daughter of feeble-minded King John II of Castile and León (1405–54) and Isabelle of Portugal, his strongminded second wife.


Isabella had a more ethical character than Ferdinand. She inherited an extensive royal lineage from several generations of European dynasties. The couple maintained exceptionally close ties to the papacy.

Isabella’s imbecilic half brother Henry IV (1425–74), also known as the Impotent, ascended the throne after their father died in 1454. Along with her younger brother, Alfonso, Isabella was brought to Henry’s court for protection and stricter supervision. Isabella became a pawn in her brother’s plans to make her future marriage economically beneficial and politically advantageous for Castile.

He wanted her to marry, among others, the king of Portugal, the French dauphin, or an English prince, all of whom she firmly refused. After Alfonso’s death in 1468, Henry proclaimed the prudent and gentle Isabella his heir on September 19, 1468, when they both affixed their signatures to the Accord of Toros de Guisiando.

Isabella secretly married her cousin Ferdinand at Ocaña, on October 19, 1469, without Henry’s consent. He disowned her, promptly revoked the Accord of Toros de Guisiando, and named his alleged daughter Princess Juana la Beltraneja (1462–1530) princess of Castile and by 1475 the wife of King Afonso V of Portugal (1432–81), as his heir. Juana was the illegitimate daughter of Henry’s wife and Beltrán de la Cueva.

After Henry died on December 10, 1474, Isabella ascended the throne on December 13 at Segovia. Her claim was immediately contested by Juana and Afonso; the struggle became a civil war. Isabella had strong support from Aragon and her countrymen.

Muhammad XII (Boabdil) surrenders to Ferdinand and Isabella
Muhammad XII (Boabdil) surrenders to Ferdinand and Isabella

Ferdinand defeated Juana’s forces at the Battle of Toro on March 1, 1476, and again on February 25, 1479. The Treaty of Alcaçova on September 1479 concluded the civil war. Juana entered the convent of Santa Clara of Coimtra in 1480.

To solidify firmer control over Spain once they became comonarchs, Ferdinand and Isabella subdued all the resistance groups, captured the insubordinate towns and fortresses, and vanquished all rebellions against their rule.

Then they proceeded to reconstruct the Cortes (Parliament), revamped the government’s administration, and produced a legal framework for Spain that granted greater power to the monarchy at the expense of the nobility, who had become dangerously powerful under previous monarchs.


When Ferdinand’s father died in 1479, Ferdinand and Isabella’s union merged the two largest kingdoms of the Iberian Peninsula and created 90 percent of present-day Spain. The astute Isabella insisted that there be joint rule and that she govern Castile herself.

The saying “Tanto monta, monta tanto” (They are one and the same), became their motto. Isabella also insisted that both their names be placed on each royal document and that she preside at each state transaction. She also allowed their coat of arms to be united.

She collected important artworks, was widely read, learned Latin after the age of 30, established schools, and supported the Franciscan order of the Poor Clares. Together they reformed the church and the monasteries in Spain, as both had become corrupt and ineffective.

The couple had five children: Isabella of Aragon (1470–98), Juan of Aragon (1478–97), Juana of Castile (1479–1551), Maria of Aragon (1482–1517), and Catherine of Aragon (1485–1536), to whom Isabella was devoted. They all received the same classical education and were taught the basics of household duties such as sewing, making beds, and cleaning.

The children were married into European royal dynasties mainly to outflank French territorial ambitions. Juan married Margaret of Austria but died within six months and left no children. Juana became insane after the death of her husband, Habsburg archduke Philip the Handsome (1478–1506). Isabella married King Afonso V of Portugal (1432–81) and then King Manuel I of Portugal (1469–1521).

She died in childbirth, and her son Miguel died within two years. Maria married her brother-in-law Manuel I of Portugal after her sister’s death. At the conclusion of at least 13 years of negotiations, Catherine married Arthur Tudor, prince of Wales (1486–1502) on November 14, 1501. Arthur died six months later.

After Arthur’s death, because her father had not yet completed payment of her dowry, Catherine would marry the future king Henry VIII (1491–1547) on June 11, 1509. He divorced her on March 30, 1533. Ferdinand and Isabella’s grandson by Juana and Philip inherited their and Philip’s parents’ huge territorial inheritance; he would become Holy Roman Emperor Charles V (1519–56).

Ferdinand and Isabella believed that religious conformity was crucially important for Spain. They also realized the political and economic advantages for their monarchy and zealously instigated the Spanish Inquisition, deeming saving souls and eradicating heresy as their most sacred duty.

During their reign, heterogeneous Spain had Europe’s largest Jewish population. Ferdinand and Isabella insisted that Spain become white (non-Moorish) and of pure Christian blood, or sangre limpia. On the threat of withdrawing military support from the pope Sixtus VI (1521–90), who deemed their actions as a plot to gain Jewish property, Ferdinand demanded that Spain initiate the Inquisition.

After a number of arguments between Ferdinand and Sixtus, the pope issued the Papal Bull of 1478 that created the Inquisition in Seville. It then expanded throughout Spain and began a lengthy period of religious cleansing.

Pope Innocent VIII (1432–92) appointed the Dominican priest Tomás de Torquemada (1420–98), Isabella’s confessor and himself a grandson of a convert, to head the Spanish Inquisition. The partially converted Jews, the Marranos, secretly maintained their Jewish cultures and customs.

To force them to confess, Torquemada imposed increasingly penurious methods. He forfeited Jewish property, which conveniently financed a war against another minority in Spain. Torquemada humiliated the Marranos by forcing them to wear a sambenito, a yellow shirt containing crosses that exposed their genitals in public.

Some 130,000 conversos were tried at tribunals from 1480 to 1492. Some Marranos were burned at the stake. The ruthless Torquemada staged the LaGuardia show trial in 1490 where no guilt was proved yet the victims were burned at the stake. Some 30,000 Jews were ritually murdered during the Spanish Inquisition.

Ferdinand and Isabella issued the Edict of Expulsion on March 31, 1492. The Jews were commanded to leave Spain and never return. With his work done, Torquemada retired to St. Thomas monastery in Ávila, where he died in 1498. Historical debate lingers about the number of victims of the Inquisition in Spain.

Ferdinand and Isabella relied greatly on the expertise of her next confessor, Cardinal Francisco Gonzalo Jiménez de Cisneros (1436–1517), who helped raise Spain to unprecedented predominance on the European continent. The couple gained control over the military orders of Calatrava, Alcántara, and Santiago, which greatly increased their power, wealth, and territory.

Ferdinand and Isabella revived the centuries-long Reconquista. They waged a costly 10-year war against the Moors and finally conquered Granada, the last Moorish stronghold, in 1491. They triumphantly entered Granada on January 2, 1492. Isabella, more so than Ferdinand, was responsible for the horrific slaughter of the Moors who would not convert to Christianity.

In 1501, Ferdinand and Isabella offered the Moors the alternative of baptism or exile; those who remained became known as Moriscos. In 1492, Pope Innocent VIII (1432–92) granted Ferdinand and Isabella the title of “Most Catholic Majesties” for spiritually unifying Spain. The Reconquista was completed.

Isabella was largely responsible for initiating the golden age of exploration for Spain. She financially supported the voyage of Christopher Columbus to the New World. She had rejected his request numerous times, but when he threatened to petition funds from France she relented and Columbus sailed in August 1492.

When he brought 150 natives to Spain, she bought some and gave them their freedom. Ferdinand and Isabella were strongly involved with the establishment of the Treaty of Tordesillas in 1494 that divided the non-Christian world overseas between Portugal and Spain.

Isabella died at Medina del Campo on November 26, 1504. Ferdinand married Germaine de Foix on October 19, 1505. Ferdinand served as regent of Castile after Juana died and later for his grandson Charles V. Ferdinand also fought in lengthy Italian Wars against France.

His generals conquered Naples in 1504, and in 1512 he annexed Navarre. He also joined the League of Cambrai in 1508 to thwart Venetian objectives and the Holy League in 1511 to counteract France. Ferdinand also founded universities.

Ferdinand died at Midrigalejo, Spain, on January 23, 1516. He is buried beside Isabella, at the Capilla Real in Granada alongside Juan, Philip, and a grandson.