The Year of Isabella I of Castile – The rivalry with Joanna la Beltraneja (Part one)

The future Queen Isabella’s half-brother, King Henry IV of Castile,  married Joan of Portugal in May 1455, with the papal dispensation having arrived at the end of 1453, as the pair were first cousins. A copy of this dispensation was not found in the archives of the Vatican, although this does not necessarily prove it didn’t exist. Their daughter’s later supposed illegitimacy was based upon a void marriage between first cousins without dispensation.

King Henry’s first marriage to the future Queen Blanche II of Navarre had remarried unconsummated, leading to rumours of King Henry’s impotence. At the time, one of the King’s favourites was Beltrán de la Cueva, 1st Duke of Alburquerque.

In any case, it took until 1462 before Joan gave birth to a daughter named Joanna. A few days later, little Joanna was baptised, and her ten-year-old aunt Isabella acted as one of her godmothers.¹ Joanna was sworn in as heiress on 9 May 1462, with Isabella and her brother Alfonso being the first to swear.

However, it appears that several nobles already doubted Joanna’s legitimacy, not in the least because of jealousy towards Beltrán de la Cueva, who held the King’s favour. Isabella later wrote that she knew why some objected to swearing the oath. She wrote, “It was something she [the Queen] had demanded because she knew the truth about her pregnancy and was taking precautions.”² Rumours about Beltrán de la Cueva being little Joanna’s biological father were beginning to circulate.

It is impossible to tell if Joanna was Beltrán de la Cueva’s daughter, but we know Joan conceived again within the year. Tragically, she lost the child, a boy, at six months. It was rumoured that a Jewish doctor named Samaya had used an early form of artificial insemination to help things along. In any case, Joanna was born, and Henry never denied that she was his biological daughter. Nevertheless, the paternity concerns made their way to Rome. A report from Pope Pius II stated that “It was said that the queen… was impregnated without losing her virginity. Some said that the semen poured into the entrance [of the vagina]  had penetrated into the most hidden places inside of her. Others believed a man other than Henry was responsible and that he so ardently desired an heir that he created the girl  as his own because it was that woman who had given birth.”³

These rumours were the perfect fuel for a rebellion.

Joanna was just two years old when a manifesto of complaints and grievances was issued against King Henry by several nobles. This led to the Representation of Burgos in 1464, where Henry was forced to recognise Alfonso as the legitimate heir.⁴ This was agreed upon with the condition that Alfonso would one day marry Joanna. However, Henry soon reconsidered, and this led to a ceremonial deposition in effigy in 1465, and the 11-year-old Alfonso was crowned as rival King. Meanwhile, Isabella was still at court with Henry and Joan.

Isabella and Alfonso were reunited in 1467 when he triumphantly rode into Segovia as Queen Joan fled. Isabella asked to return to her mother at Arévalo, and at the end of the year, they celebrated Alfonso’s 14th birthday with the three of them. They stayed there until they were forced to flee due to an outbreak of the plague at the end of June 1468. Alfonso fell ill at Cardeñosa, and for four days, he fought for his life. His death was expected, and Isabella wrote, “And you all know that in the moment that the Lord decided to take his life, succession of the kingdoms and royal lands of Castile and Leon will, as his legitimate heiress and successor, pass to me.”⁵

Alfonso died on 5 July 1468. The battle was now between Joanna and Isabella.

Joanna was raised by the Mendoza family between 1465 and 1470. And then by Juan, Marqués de Villena from 1470 to 1475. Joanna’s mother, after having fled in 1467, had fallen pregnant by a lover, which only seemed to bolster the rumours of Joanna’s illegitimacy, although she continued to support her daughter’s claim. During this time, Joanna was considered for several marriages. In 1470, she was betrothed to the Duke of Guyenne, but he died in 1472.

Her father died on 11 December 1474, and her aunt Isabella successfully claimed the throne of Castile. It is not clear if Joanna and her mother were present when Henry died. After a few more marriage proposals, Joanna was married to her maternal uncle, King Afonso V of Portugal, on 29 May 1475. King Afonso invaded Castile to support Joanna’s claim shortly after their betrothal ceremony on 1 May. Shortly after her marriage, her mother, Joan, also died. Joanna was still only 13 years old, while her aunt was a mature married woman with a daughter of her own. Afonso did not consummate the marriage with his 13-year-old niece as he went to war.

Meanwhile, Joanna sent out letters to the cities and towns of Castile which read, “During his lifetime, he always wrote and swore, both in public and in private, to all those prelates and grandees who asked about it and to many other trustworthy people that he knew me to be his true daughter.”⁶ She also claimed that her father had named her as his heiress on his deathbed and that he had been poisoned by Isabella and her husband, Ferdinand. She called for Isabella to be punished, saying, “You must all rise and join, serving, helping and ensuring that this abominable, detestable action be punished.”⁶

Read part two here.

1. Juana de Castilla, mal llamada La Beltraneja by Tarsicio de Azcona p.22
2. Isabella of Castile by Giles Tremlett p.32
3. Isabella of Castile by Giles Tremlett p.33
4. Due to male-preference primogeniture, Isabella was behind Alfonso in the line of succession/
5. Isabella of Castile by Giles Tremlett p.40
6. Isabella of Castile by Giles Tremlett p.124