Joanna of Castile

Lore & Background

Joanna was the fourth child but third surviving of Isabella I of Castile and Ferdinand II of Aragon. She had a fair complexion and brown eyes, with hair described as between strawberry-blonde and auburn, resembling her mother and her sister Catherine. Her formal education was extensive, covering astronomy, canon and civil law, genealogy, heraldry, geography, grammar, history, languages, mathematics, philosophy, reading, spelling, and writing. She studied the Iberian Romance languages of Castilian, Leonese, Galician-Portuguese, and Catalan, and became fluent in French and Latin. Her training also included baking, chess, cooking, court etiquette, dancing, drawing, equestrian skills, good manners, music, needle arts such as embroidery and lace-making, and singing. She learned hawking and hunting, and was skilled at playing the clavichord, guitar, lute, and monochord. Joanna was married by arrangement to Philip of Austria in 1496, a union designed to strengthen alliances against French power. After the deaths of her elder brother, elder sister, and nephew, she became heir presumptive to Castile and Aragon. Upon her mother’s death in 1504, she became Queen of Castile. Her husband briefly ruled as King of Castile before his death in 1506. Despite being the ruling queen, she was declared insane and confined in the Royal Palace in Tordesillas under her father’s orders, who ruled as regent until his death. Her son Charles then became king, with Joanna nominally co-monarch but remaining confined until her death at age 75. Historians debate whether her alleged madness was genuine or used to discredit her.

Reader's Guide

Joanna of Castile's significance lies in her role as a transitional monarch between the Trastámara and Habsburg dynasties in Spain. Despite being the ruling queen of Castile and later Aragon, she had little effect on national policy due to her confinement under claims of insanity. Her marriage to Philip the Handsome initiated Habsburg rule in the Spanish kingdoms, and her son Charles I became a powerful emperor. Historians continue to debate whether her alleged madness was genuine or a political tool used to discredit and control her. Her confinement set a precedent for the marginalization of female rulers, and her story raises questions about mental health, gender, and power in early modern Europe. Her legacy is thus both as a queen who inherited vast realms and as a figure whose agency was stripped away by those around her.

Did You Know?

• Joanna was educated in astronomy, canon and civil law, genealogy, heraldry, geography, grammar, history, languages, mathematics, philosophy, reading, spelling, and writing.
• She was skilled at playing the clavichord, guitar, lute, and monochord.

Education and the Making of a Sovereign

Though born into a dynasty where daughters were not expected to inherit, her upbringing was anything but casual. Her tutors included the Dominican friar Andrés de Miranda, the court educator Beatriz Galindo, and her own mother. The curriculum spanned astronomy, canon and civil law, genealogy, heraldry, geography, grammar, history, mathematics, and philosophy. She read the Christian poets Juvencus and Prudentius, the Church fathers Ambrose, Augustine, Gregory, and Jerome, and the Roman statesman Seneca. Beyond the classroom, she mastered baking, chess, cooking, court etiquette, dancing, drawing, equestrian skills, embroidery, lace-making, needlepoint, sewing, spinning, weaving, and singing. She spoke Castilian, Leonese, Galician-Portuguese, and Catalan natively, and became fluent in French and Latin. She played the clavichord, guitar, lute, and monochord, and pursued hawking and hunting in the outdoors. This was a formation designed not merely for a princess but for a woman who might one day hold a crown.

The Habsburg Alliance and a Life Apart

Philip's parents, Emperor Maximilian I and the late Duchess Mary of Burgundy, sought to bind the Habsburg and Trastámara houses together as a bulwark against the expanding ambitions of France. In August of that year she set sail from the port of Laredo on the Bay of Biscay, beginning a journey to Brabant that would separate her permanently from her family.

Heir by Loss, Sovereign by Right

That same year the Aragonese Cortes met in Zaragoza to swear an oath of succession in her name, though Archbishop Alonso de Aragón insisted the gesture carried legal force only as a formal compact between the Cortes and the king. A grand fealty ceremony followed in Toledo, where Joanna received oaths from the Castilian Cortes; the event was recorded in meticulous detail by the chronicler Antoon I van Lalaing. After Philip and most of the court departed for the Low Countries, a pregnant Joanna remained in Madrid, where she gave birth to her son Ferdinand, who would later become Holy Roman Emperor as Ferdinand I.

Confinement, Madness, and the Long Silence

What followed was the most devastating chapter of Joanna's life. Upon Ferdinand's passing, Joanna inherited the Aragonese crown as well, making her queen of both kingdoms. Her son Charles I then ascended the throne, and Joanna was nominally his co-monarch, yet she remained a prisoner in Tordesillas for the rest of her days. Whether her alleged madness was genuine or a political instrument deployed to strip her of authority remains one of the most fiercely debated questions in Spanish historiography, and the epithet 'the Mad' has followed her name across centuries.