Joanna of Castile, also known as Joanna the Mad, was a Spanish princess born on November 6, 1479. She was the daughter of Ferdinand II of Aragon and Isabella I of Castile, the Catholic Monarchs who unified Spain. Joanna became the Queen of Castile in 1504 after her mother's death, but her reign was marked by personal struggles and political challenges. Joanna was married to Philip the Handsome, the Duke of Burgundy, and they had six children, including Charles V, who later became Holy Roman Emperor. Her mental health issues led to her being declared unfit to rule, and she spent much of her life confined in a palace, overshadowed by her son’s authority.