In challenging her half-brother Henry IV for the crown of Castile, Isabella sought the ability to choose her own husband. Once Henry agreed to name Isabella his heir, the Castilian nobles entered a rivalry for control of her, as well as who she chose for a spouse. Francisco Jiménez de Cisneros, Archbishop of Toledo, her most powerful supporter, had already contacted Juan, King of Aragon, and together they identified Juan’s son Ferdinand as the ideal candidate. Throughout all the scheming, Isabella insisted she had the last word on the decision.

In June 1468, Juan had given Ferdinand the title of King of Sicily and allowed him to exercise royal power in his absence. Juan sent bribes to Castilian nobles to pave the way for support of the marriage, and Isabella and Ferdinand began a steady flow of communication through letters. By Christmas, Isabella deliberated the most important decision of her life. Either she gave in to Henry, accepted the noblemen’s power over the monarchy and married the Portuguese king, or she married the man of her choice and risked a protracted civil war.

King Juan sent an ambassador to Castile with considerable cash to bribe Isabella’s closest advisors, and secret meetings took place at night in Isabella’s rooms. Isabella kept the negotiations going, sending her chaplain to view Ferdinand and another suitor, Charles, Duke of Berry, brother of King Louis XI of France. She was delighted with his report on the superiority of Ferdinand’s appearance. By January 1469, she had decided to marry Ferdinand and a proxy marriage took place before witnesses.

The populace of Ocaña voiced their support for an Aragonese marriage over a Portuguese match, making Henry uneasy. In March, Henry planned to travel to Andalusia to manage some administrative problems, and he ordered Isabella to stay in Ocaña, and to make no marriage plans, even having a Castilian nobleman threaten her with arrest. The king departed in early May.

A final secret marriage treaty ensued. Ferdinand could administer justice in Castile, but all other policies would have to be agreed, signed or done with Isabella’s permission. Ferdinand would provide 10,000 florins once they consummated the marriage and an army of 4,000 lancers to defend Isabella against her enemies. Another 20,000 florins would be paid up front, along with a valuable pearl and ruby necklace. Isabella now made her excuse to leave Ocaña.

She planned to oversee preparations for the ceremonies in Arévalo to commemorate her brother Alfonso’s death. She departed on horseback with two servants. After visiting her brother’s tomb, she went to visit her mother in Madrigal de las Altas Torres. Along the way, she lost some of her closest friends and allies by opposing Henry and the King of Portugal, as some of her women were also bribed to spy on her.

Ferdinand planned to go to Valencia to pick up the valuable necklace mentioned in the marriage treaty. He would have to infiltrate Castile without being caught, which he did by traveling incognito, dressed as a mule driver. Isabella would eventually make her way to Valladolid, which she deemed a safe place to meet Ferdinand. Henry agreed Isabella could consider four candidates as husband: Ferdinand, Afonso V of Portugal, Charles, Duke of Berry, and the future Richard III of England. In the meantime, the Portuguese king expected the finalization of the marriage treaty, while Henry knew Ferdinand would enter Castile for Isabella’s consideration.

On October 14, Isabella and Ferdinand first met at midnight in the home of Castilian nobleman Juan de Vivero, a relative of the archbishop of Toledo. Ferdinand arrived by horseback with three retainers and came in through a back entrance. Upon entering Isabella’s room, they gazed at each other with admiration; instantly attracted, the couple spoke for two hours.

Isabella and Ferdinand exchanged formal promises to marry, which were recorded and notarized. The archbishop then read the marriage agreement. The couple were second cousins and needed papal dispensation for the marriage. This they did not have. So, after some bribery, a false dispensation had been obtained and was read for the ceremony. The archbishop then declared they should marry as soon as possible.

On October 19, 1469, a modest religious ceremony took place in the great hall of the Vivero palace, followed by a nuptial mass. They had to borrow money for the festivities. Official witnesses to the ceremony were Ferdinand’s grandfather and aunt and around two thousand people of all estates: lords, knights, royal justices, and priests. With witnesses playing kettledrums, flutes, and trumpets as they entered the bridal chamber, the couple duly consummated their marriage. They displayed the bloodstained sheets to the crowd outside the next day.

The secret had been revealed and seven days of celebrations ensued in Valladolid. The townspeople cheered the young couple as they rode through the streets. Although unseen at the time, a new dynasty established itself, beginning a cultural golden age that would alter the course of Spanish history.

Further reading: “Isabella the Queen: Life and Times” revised edition by Peggy K Liss, “Isabella of Castile: Europe’s First Great Queen” by Giles Tremlett, “Isabella: The Warrior Queen” by Kirstin Downey