Winning the crown of Castile

Isabel of Castile

Castile was governed after King Sancho IV’s death by Maria de Molina, who was regent first for her son, who became King Fedinand IV, and then her grandson, before they were old enough to be crowned. She died in 1321 and her grandson ruled as King Alfonso XI. During Alfonso XI’s reign the Merinis were driven from Gibralter and Algeciras between 1340 and 1344 at the Battle of Río Salado. Castile, however, was torn apart by feuding lords and much of his early reign was spent in brutal repression within Castile. It would be a wedding not a war that would unite Castile, León and Aragon, and create the first unified kingdom of España.

Queen Isabel I of Spain was born into the line of Trastámara, which began in 1369 with the reign of Enriqui II of Castile. Her mother, Isabella, was the second wife of King Juan II of Castille, whose marriage to Maria de Aragon had produced four children, only one of which survived, to become Enriqui IV of Castile. Prince Enriqui, in turn, was married to Blanca de Navarra, but after seven years the marriage was still unconsummated, earning Enriqui the unofficial title of “El Impotente.” King Juan now had a problem; his only son could not produce an heir to the throne of Castile. His close adviser and friend, Álvero de Luna, suggested that he remarry, and proposed 19-year old Isabella as a likely candidate. The only obstacle to this marriage was that his first wife Blanca was still alive. In 1446, Blanca mysteriously died, leaving the way open for Juan to marry Isabella, and gave rise to rumors that Álvero de Luna had poisoned Blanca. Nevertheless, the wedding preparations continued, and at the age of 42, King Juan married Isabella in July 1447, hoping that she would give him a male heir to continue the Trastámara line.


Before the ink was dry on the marriage documents, Álvero began to dominate the new queen and her husband, even to the point of trying to control their marital couplings. The young Isabella railed at this interference and tried to convince Juan to get rid of his closest and most-trusted adviser.

During her confinement, there were bouts of sickness, and Isabella suspected that the evil Álvero was trying to poison her too. Finally, she gave birth to a daughter whom they named Isabel, but she knew she must find a way to eliminate the threat that Álvero de Luna posed to her, and the life of her daughter.

Six years after Isabel and Juan’s wedding, De Luna made a fatal mistake. One of the nobles had openly defied him, and Álvero had him thrown from a high window to his death. Isabella badgered her husband to have him arrested for murder, and when the witnesses described what had happened, King Juan had no alternative but to order Álvero de Luna’s execution. With the threat to her life removed, Isabella faced a new problem as the health of her husband slowly deteriorated. She gave him a son, Alfonso, in November 1453, but by the following July, Juan was dead.

The succession to the throne of Castile was clouded, and the nobles began to take sides depending on which candidate for the crown offered them the best opportunities for advancement. The true heir was crowned as King Enriqui IV of Castile, but he was impotent and could produce no children, leaving young Alfonso and Isabel as next likely candidates.

Enriqui always claimed that he hated Blanca and the marriage was cursed. Finally, Blanca successfully petitioned the Pope to annul the marriage on the grounds of impotence. She later married Juan II of Aragon and had two children by him. 

Enriqui married again, this time to Juana de Portugal knowing that he would have to produce an heir to end the doubts. In 1462 she gave birth to a girl, but many of the nobles doubted that Enriqui was her true father. They believed that Enriqui’s close friend, Beltrán de la Cueva, a known lover of Juana, was the father. To bolster the legitimacy of his daughter's lineage, he gave her the title of Princess of Asturias, which is a title usually given to the heir of the Spanish crown. He invited all the nobles to the christening and made them swear allegiance to her, but the disquiet over her true father continued to fester, and they gave her the unflattering name of Beltraneja; a name that has stuck with her throughout Spanish history.

His noblemen were unhappy and pressured the Enriqui to name his half-brother Alfonso as his heir instead. He was offended, but he acquiesced and named him as successor in 1464. He had made a terrible mistake, because the following year, the same nobles proclaimed 11 year-old Alfonso as king, and Enriqui had to fight to keep his crown. 

A civil war broke out in Castile over King Enriqui’s inability to act as sovereign. He now needed a quick way to please the rebels of the kingdom. As part of an agreement to restore peace, Isabella was to be betrothed to Pedro Girón Acuña Pacheco, Master of the Order of Calatrava and brother to the King's favourite, Juan Pacheco. In return, Don Pedro would pay into the impoverished royal treasury an enormous sum of money. Seeing no alternative, Enriqui agreed to the marriage. Don Pedro was a brutal drunken lout. Isabella was aghast and prayed to God that the marriage would not come to pass. Her prayers were answered when Don Pedro suddenly fell ill and died while on his way to meet his fiancee. The civil war went on for three years, and only ended when young Alfonso died mysteriously. Now there were only two choices for who would inherit the crown after Enriqui; Juana or Isabel.

Isabel had enough followers to defend her claim to the crown and the dispute broke into open civil war again. Finally, Isabel and Enriqui met at the Bulls de Guisando in Ávila on September 18 1468 and negotiated a truce, which included agreeing to name Isabel as heiress to the throne and give her the title of Princess of Astorias. He was again under pressure from the nobles, many of whom wanted to crown Isabel queen before he was dead. The Church had sided with Isabel, and called into doubt the validity of his daughter Juana's lineage and the king sought to marry her back into a royal family to regain her title.  

Isabel had made herself the most desirable, yet most dangerous woman in a boiling political stew of conflicting loyalties and alliances. Enriqui and his nobles tried to marry her off in power deals with other kings, but she evaded all attempts at an arranged marriage, and despite pressure from the nobles, she steadfastly refused to take the crown from her half-brother before he was dead.

The brother of the King of France and the King of Portugal paraded themselves before her, but she remained unmoved by them. The only candidate that Isabel had any interest in was the son of the King of Aragon. He had originally been betrothed to Isabel, but had been brushed aside by events. Aragon had just fought a war with France, and Isabel marrying into French royalty would be a disaster for the kingdom. The only problem was that Isabel and Ferdinand were second cousins, and the Church forbade their union because of the danger of inbreeding. Nevertheless, her advisers began negotiations for the wedding.

Meanwhile, Enriqui had depleted the coffers of Castile with constant wars, and the main reason he was forced to sign the peace treaty of Guisando was a lack of money to continue fighting. Enriqui tried to raise an army to contest the wedding, but found that his impoverished nobles refused to fund another war. To make matters worse, Andalucia withdrew financial and military support, making him virtually powerless to stop the wedding. 

The secret wedding negotiations were not going well. To Ferdinand's dismay, Isabel was implacable about relinquishing her claim to the crown of Castile, and she stipulated that the pre-nuptial agreement gave them equal power to rule over the kingdom. The deal was called “tanto monter, monter tanto” meaning that whoever rules, it comes out the same.

In a desperate attempt to block the marriage, Enriqui took Isabel's mother away and kept her in isolation in the castle at Arévalo. Knowing that Isabel would follow her, he had conceived a plan that would imprison them both away from her advisers without the use of force. He could now lead her into a marriage with Luis, whose father had died, and who had now become the King of France. 

Isabel’s mother was deteriorating mentally and she suffered bouts of hallucinations an frequently could not recognize her own children. Alone, and in great danger, she was constantly badgered to sign a marriage proposal from the French King. One of her trusted friends rode to rescue her, bringing a gift from the King of Aragon, a necklace of rubies and pearls. Isabel made up her mind in an instant and rode off with him, leaving her mother with her enemies. 

Isabel and Ferdinand: Artist unknown.


So far, Isabel and Fernando had never met. The capitols of the two Kingdoms were two hundred miles apart, and Enriqui controlled the borders of Castile. Fernando disguised himself as a servant, and with two aides, passed over the border into Castile to meet with Isabel. To everybody’s delight, the two fell in love, and the wedding plans accelerated.   

Enriqi's only hope of stopping the wedding now was through the Church. His spies had discovered the weak point in their plans. A papal bull had been drawn up by the previous Pontif, Pius II, allowing second cousins to marry, but he died before he could sign it. Through the bishop of Toledo, Isabel and Fernando had been petitioning his successor Pope Paul II to uphold the bull and give the marriage his blessing. The Pope refused, and the marriage of Isabel and Ferdinand was forbidden. 

In secret, the Bishop obtained the unsigned Papal bull and forged the old Pope’s signature. They read this to the couple, who were delighted that their marriage had papal blessing. In Enriqui’s court, they knew the truth, and a letter was sent to Isabel by one of her friends in his court telling her about the forgery.


Isabel was furious that her trusted advisors would lie to her and lead her into a trap. With great tact, they persuaded her that the Pope would be led by events. If they married, then he would have to give his consent. Still in secret, Isabel had her mother and handmaiden friends brought to her side, and they were all reunited when Isabel married Ferdinand at the Palacio de los Vivero in Valladolid on the 19 October 1469.   

The true power over the kingdoms had now passed to Isabel, effectively uniting Castile, León and Aragon to form the basis for one state, which became the nascent country called after its ancient name of Hispania, and later changed to España. The united kingdoms still continued to govern themselves as separate entities, but the seeds had been sown for something greater.

Enriqui flew into a rage. He was still the King of Castile, but in name only.

Juan Pacheco, the Marquis of Villena, and his followers maintained that Joanna la Beltraneja, daughter of King Henry IV, was the rightful queen. Shortly after the Marquis made his claim, a long-time supporter of Isabel, the Archbishop of Toledo, left Isabel’s court to plot with his great-nephew the Marquis in an attempt at reconciliation, and to seek a compromise over succession. Isabel met with her half-brother and her husband Fernando. A deal was arranged to give Enriqui some measure of respect, and reassurance of his royal lineage, but two things happened to change their plans. Firstly, the thorn in everybody’s side, Juan Pacheco, died suddenly in Trujillo on the 1st October 1374. His son ingratiated himself with King Enriqui and stepped into his dead father’s shoes, but shortly after, Enriqui himself died, and on the 13th December 1347 Isabel was crowned Queen of Castile.

Their plans to depose Isabel thwarted, the Archbishop of Toledo and Diego Pacheco made plans to have 13 year-old Joanna marry her uncle, King Alfonso V of Portugal and invade Castile to claim the throne. In May 1475, King Alfonso of Portugal and his army crossed into Spain and advanced to Plasencia. Here he married the young Joanna and started a war for the Castilian crown. The war raged back and forth for almost a year until 1 March 1476, when the Battle of Toro took place, a battle in which both sides claimed victory, but neither won.

The armies fought each other to a standstill, but the battle was indecisive, and King Alfonso was forced to retreat and regroup his forces. Ferdinand showed his genius by sending messengers out to all the cities of Castile and the kingdoms nearby that he had crushed the Portuguese in a great military victory. Overnight, support for Joanna collapsed. To avoid further bloodshed and a war they could not afford, Isabel and Fernando granted King Alfonso of Portugal the exclusive right of navigation and commerce in all of the Atlantic Ocean south of the Canary Islands, which meant that España was practically blocked out of the Atlantic and deprived of the gold of Guinea. The treaty of Alcáçovas, as it was known, created unrest among Andalucia’s nobles who feared that they had bought peace at too high a price and had restricted their expansion into the Atlantic. 

Meanwhile, Isabel took advantage of her husband’s winning ploy and convoked courts in Segovia in 1476, where her eldest child, Isabella was proclaimed as heiress to the crown of Castile, thus legitimizing her own claim to the throne. Later the same year, inspired by her husband’s successes in battle, Isabel led an army against an uprising in Segovia while Ferdinand was fighting elsewhere. She successfully negotiated a peace deal with the rebels, much to the surprise of her military advisers. Two years later, Isabella further secured her place as ruler with the birth of her son, John, Prince of Asturias, on 30 June 1478. To many, the presence of a male heir legitimized her place as ruler

In 1479, Fernando’s father died and he became King of Aragon, and with Isabel as his wife, the kingdoms of Aragon, Castile and León became a united country; but it was a bankrupt country. Isabel and Fernando had run up huge debts fighting for the crown. The Church did not lend money, they just collected it, and the only people who had been untouched by the costly Christian wars were the non-Christians who lived within their lands. They were not obliged to fund armies or fight, but they had profited well from the costly wars. They were predominantly Jews and Moors, who had served as doctors, builders, metalworkers, joiners and accountants.

They had never had full equal rights within Christian lands, and were taxed more than their Christian counterparts, but with most of the people around them starving because of the loss of agricultural workers, and their strange, secret and different religions, they soon became the focus of suspicion and hostility. 

Law and order had broken down within Castile and Aragon, and Isabel and Ferdinand created a militia whose sole purpose was to police their kingdoms and eliminate the robber bands that plagued traders. She gradually gained more control of the economy, and stability returned, but a cancer was growing in the form of hatred and intolerance for those who were not of their faith. Posters began to appear depicting Jews as necromancers with dark and evil rituals. To the south of the united Christian kingdoms, lay the rich farmlands of the Islamic Emirate of Granada. 

In 1478, while Ferdinand and Isabella were still consolidating their kingdom, they made formal application to the Pope for a tribunal of the Inquisition in Castile, to investigate these and other suspicions. 

With growing certainty, and the urging of the Pope, Isabel realized where the money to fill her coffers was going to come from.