Joanna of Castile: The Bastard Daughter

     Joanna was the only child of King Henry IV of Castile and his second wife, Joan of Portugal. Henry IV was the older half brother of the future Queen of Castile, Isabella. How Isabella took the throne instead of Joanna is based on one factor: paternity. 

     Henry IV had been married to his first wife and cousin, Blanche of Navarre, in 1436. Blanche would become queen in her own right of Navarre, a neighbor of Castile. A marriage between these two kingdoms would increase stability on the Iberian peninsula. However, by 1453, the Bishop of Segovia was forced to annul this marriage, due to infertility. Curiously, instead of directly blaming Blanche for the problem, the cause was stated to be a curse against Henry that rendered him impotent. Henry claimed that he had tried to consummate the marriage for three years, but could not. Meanwhile, prostitutes in Segovia testified that Henry had no problem laying the pipe. Surely, the only reason why he was unable to get Blanche pregnant was a curse. Blanche was examined and found to still be a virgin. She was sent back to her family where she was imprisoned. She eventually was the Queen of Navarre in name only, and was ultimately poisoned to death. 

Henry IV of Castile, father of Joanna 

     Forging a new political alliance, Henry married his other cousin, Joan of Portugal. Joan quickly gave birth to a daughter, but it was said that the father was not Henry, but rather Beltran de la Cueva, the Duke of Albuquerque. Joanna was often called La Beltraneja in reference to her paternity. The rumors of her birth caused dissatisfied nobles to rebel, preferring to put Henry's half brother, Alfonso, on the throne instead. Joan continued affairs behind her husband's back. Ultimately, Henry conceded to his nobles wishes, and disinherited Joana as the Princess of Asturias, naming his brother Alfonso as heir instead. Henry reneged on his promise, and again proclaimed Joanna as heir. This began a series of civil wars. 

Joan of Portugal, mother of Joanna 

     Ultimately, Alfonso died young and his claim passed to his sister, Isabella. Isabella and Henry reached an agreement in which she was recognized as his heir, and he begrudging excepted this truce until his death. 

     After Henry's death, war broke out again. Joanna's Portuguese relatives wanted her on the throne of Castile and denied Isabella's claim. Her uncle, King Alfonso V of Portugal, promised to marry her and support her claim. Meanwhile, Isabella was supported by her husband, Ferdinand of Aragon. Isabella and Ferdinand proved successful in the war, causing Alfonso to annul his marriage too Joanna. Joanna was no longer Queen of Portugal or Queen of Castile. 

Joanna of Castile, La Beltraneja

     Joanna was given the choice to enter a convent or marry Isabella and Ferdinand's one year old son. Joanna chose the convent. She maintained cordial relations with Isabella and outlived her aunt, although she continued to sign her letters as Queen. It is said that when Isabella died, Ferdinand tried to marry Joanna, so that his daughter couldn't take control of Castile. This didn't happen and ultimately, Joanna died peacefully, with her heir by law being Isabella's daughter, Joanna, anyway.