Much like his contemporary Arthur Tudor, Prince Juan was considered to be a future King who would solve all problems. He would united a divided country, like his father and mother had done, his marriage would tie him to important European allies, and he would be raised with an education suitable to mould him into one of his countries greatest monarchs. Unfortunately, like Prince Arthur, it would fall apart all too soon.  

Arriving in the world in June 1478, the birth of a healthy son was a huge relief to his parents. Queen Isabella of Castile and King Ferdinand of Aragon had been married for nine years and all they had to show for it was a daughter, the Infanta Isabella. Now they had a new baby in their nursery, and a boy at that. Nine days after his birth he was carried to the cathedral in a grand procession, giving the people of Seville an early glimpse of their future king.

Juan was too precious to be kept far from his parents. Although his paternal grandfather, the King of Aragon, wasn’t keen on the idea of his grandson growing up in Castile, Isabella appointed the wet nurse herself and had the prince’s household kept as part of her court. There would be no long wait for more children. As he grew up Juan was followed by Juana in 1479, Maria (who was one of twins, sadly her sister was stillborn) in 1482, and Catalina in 1485. Since no brothers came along to join the prince, everyone was focused on raising him to be the first King to rule the united kingdoms of Castile and Aragon.

Finding a bride

Juan’s importance as sole male heir meant that possibilities for his future marriage were entertained early on. He was less than a year old when his mother proposed him as a candidate to marry her rival to the Castilian throne; Juana “la Beltraneja”. Juana had used (and been used by) the Portuguese to try and claim Castile and one of the proposals for a peace treaty included a clause to remove her entirely as a threat. She could either choose to be betrothed to Juan and wait for him to grow up, or join a convent and become a nun.

Juana chose the convent life. But it shows the lengths that Queen Isabella would go to in order to secure a peaceful kingdom for herself and her heir. La Beltraneja could not be allowed to marry another and deliver babies that would be rivals to Juan.

Other potential brides that were proposed over the years included Anne, the Duchess of Brittany in her own right, and Katherine of York, a younger daughter of King Edward IV and his wife Elizabeth Woodville. Like Isabella and Ferdinand, Edward and Elizabeth had a bevy of daughters to marry well, and matches were arranged with the kingdoms of France, Scotland and Denmark, and the Duchy of Burgundy. Edward’s early death in his 40s meant that none of them came to pass, which ultimately benefited the Spanish.

Life in the court

In 1481 Juan moved with his parents to his father’s kingdom of Aragon. His paternal grandfather had died making Ferdinand king, and as with his baptism in Castile young Juan could be shown off to the people as their future monarch. The Aragonese court assembled together and swore to recognise the toddler as heir to the throne.

There were more court appearances for Juan as he grew up. In 1489 a group of English envoys arrived to negotiate a marriage between one of the sons of King Henry VII and one of Juan’s sisters. Over several days of official meetings various members of the family were brought in to meet the envoys. Juan and his older sister Isabella were introduced on the second day, with Juan dressed in a handsome outfit of red velvet trimmed with ermine fur. He also joined his family several times over the following days when celebrations dancing, feasting and jousting were held.

When he wasn’t needed for official court functions Juan was being given an education fit for a King. He was taught Latin, as were his sisters, as well as grammar, ethics, arithmetic, and several musical instruments. His parents regularly brought him into their courts so he could personally watch as they governed both their kingdoms. He had to learn to ride well from an early age, as his parents moved around the country fighting a war to drive out their Muslim neighbours. As a more sedate pasttime he learned to play chess and cards and mastered several musical instruments.

As a Prince it was expected that Juan would pass down his clothes before they became too ragged and dirty. It was one of the perks expected from members of his household. However, as a young man Juan appears to have been extremely reluctant to let go of his old belongings. In the end his mother intervened and had an inventory made of his wardrobe, then stood and watched him give away many of his clothes. Perhaps he enjoyed being fashionably dressed, or perhaps he liked to keep his purse strings firmly closed, but as long as his mother was around Juan would not be allowed to be miserly towards his servants.

At the age of twelve another ceremony was held in which Juan was officially recognised as a knight. This involved him spending more time with his father learning how to be a soldier. At the age of fourteen he had been granted extensive lands and property that meant he was receiving a healthy income, and his parents set him up with his own independent household that he would need to learn to manage and govern himself, a mini kingdom of his own.

Becoming a military leader was physically demanding and there are signs that Juan was not as healthy as some of his contemporaries. He suffered frequent stomach problems that were treated with plain chicken and tortoise meat, but that meant his weight fluctuated. In 1488 he contracted smallpox but luckily survived it.

Three weddings and a funeral

In the summer of 1496 Juan and his family waved farewell to his younger sister Juana as she set off by ship to the Netherlands, where she would marry Philip “the Handsome”, Duke of Burgundy. The following spring he was with his family once more to welcome his own fiance, Philip’s sister Margaret of Austria. The poor girl had faced a terrible time at sea and at one point had feared that she was going to drown. But the storm had abated and she had eventually arrived safely in Spain. The wedding was held in March 1497 but due to Lent they had to wait several weeks before they could consummate their marriage.

Margaret had grown up in the French court as she had been betrothed to the underaged King of France. After the betrothal had been broken she had spent several years living with her namesake and step-grandmother, the Dowager Duchess of Burgundy Margaret, a sister of King Edward IV of England. The elder Margaret had never had children and the early death of her step-daughter meant she took on a motherly role to the two children left behind. The younger Margaret had seen how a strong woman could rule, so she was almost certainly well prepared to support Juan in the same way Queen Isabella supported Ferdinand.

The newlyweds fell passionately in love. They were of a similar age, they were both well educated, and together they made a charming couple. But some of the Spanish courtiers began to worry about Juan. He was now eighteen years old and seemed to be completely engaged with the honeymoon phase. He alternated between riding out hunting and spending an indecent amount of time in bed with his lovely young wife. His doctors recommended that he and Margaret be separated for a time so they could both rest but Isabella refused the suggestion. She may have been keen for Juan, who was still the only male heir in the family, to start making sons as quickly as possible. Or perhaps she doubted that anyone could persuade a pair of married eighteen year olds to stop having sex, even for the sake of their health.

1497 was a year of weddings for the Spanish monarchs. Once Juan and Margaret were celebrated and settled, attention turned to the Infanta Isabella. Her first husband, Prince Afonso, had died six months after their wedding. Now there was a new Portuguese king and young Isabella had been persuaded to marry him. In September the family gathered once more and started the journey to escort Isabella to the border with Portugal and hand her over to her new husband.

The family moved on while Juan and Margaret, who was weeks into her first pregnancy, stayed behind at Salamanca. Juan had complained of suffering from exhaustion and soon after his parents left he took to his bed with a fever. When his parents received a letter outlining his condition Ferdinand turned around and raced back to Salamanca. He arrived in time to say his goodbyes to his only son. Juan died on 4th October 1497 at just twenty years old. He was buried in Avila.

Despite the care of her in-laws, Margaret ultimately went into early labour and delivered a stillborn baby girl. She returned to the Netherlands. Infanta Isabella, Queen of Portugal, died giving her mother a new male heir. But the baby, Prince Miguel, died in his infancy. Ultimately the monarch who would unite the two kingdoms of Spain was not Juan or a son by Margaret, but his nephew through his sister Juana; Charles.

Last months Almost King was Philip of France.