Katherine of Aragon's sisters

Juana, Isabella and Maria

Juana of Castile (Master of Affligem, National Sculpture Museum, c. 1500).

Juana of Castile

Juana, also spelled Joanna and unfortunately and unfairly known as ‘Joanna the Mad’ was the third surviving child and second daughter to Isabella of Castile and Ferdinand II of Aragon. Older sister to Maria and Katherine, younger sister to Isabella.

Juana was born in Toldeo, Castile on November 6th, 1479. She became heiress with the deaths of her father and older sister, Isabella in 1500. Her son Charles with Philip the Handsome who would become Holy Roman Emperor Charles V was also born early this year.

Juana and Philip stained glass (Basilica of the Holy Blood in Bruges).

Juana and Philip had married in 1496 until his death in 1506. They had six children. Their sons Charles and Ferdinand would both go on to become Holy Roman Emperors. Their daughters became European queens.

• Eleanor: Queen of Portugal and France

• Isabella: Queen of Denmark

• Mary: Queen of Hungary

• Catherine: Queen of Portugal

Her husband Philip and her mother Isabella both died within a short period. This was likely devastating to Juana. This is where the public started to label her as “mad” or “mentally ill.” Her husband and mother both passed away. Her father treated her terribly during his lifetime and her sons were not much better.

Juana spent the last years of her life locked away, considered “unfit” to rule the kingdom she was heiress to. She was kept in the Royal Palace in Tordesillas, Castile. Her son Charles wanted to rule in place of his mother. Juana remained locked away in the Royal Palace until her death on April 15th, 1555. She was seventy-five.

Juana’s burial site (The Capilla Real in Granada).

Isabella of Aragon, Queen of Portugal

Infanta Isabel de Trastámara (The Huelgas Monastery).

Isabella of Aragon, Queen of Portugal was the eldest child born to Isabella and Ferdinand on October 2nd, 1470 in Dueñas, Castile. She was born during the reign of her uncle, Henry IV. There was tension between Henry and her mother Isabella.

When her mother Isabella of Castile claimed the throne of Castile upon Henry IV’s death in 1474, Isabella became heiress presumptive to the throne of Castile. Unfortunately Isabella predeceased her mother. With Isabella’s untimely death Juana was now heir.

Isabella had been married twice within her short life. Her first husband was Alfonso, Prince of Portugal (m. 1490-his death 1491) and her second husband was Manuel I, King of Portugal (m. 1497-Isabella’s death 1498). Isabella and Manuel had one child together, a son Miguel da Paz, Prince of Portugal born in 1498. Isabella tragically died almost immediately after the birth of her son. Miguel himself would die only a year later.

Maria of Aragon, Queen of Portugal

Maria was the second youngest surviving child to Isabella and Ferdinand, older sister to Katherine. She was born on June 29th, 1482 in Córdoba, Castile. Isabella had been pregnant with twins, but Maria’s twin had been delivered stillborn.

Maria married her sister Isabella’s widow, Manuel I of Portugal in 1500. Maria was Manuel’s second wife and he would go on to marry a final time after her death. They had several children together.

• John III: Succeeded his father as King of Portugal.

• Infanta Isabella: Married her cousin Charles V, Holy Roman Emperor.

• Infanta Beatrice: Married Charles III, Duke of Savoy.

• Infante Luis, Duke of Beja: Unmarried but had illegitimate children.

• Infante Ferdinand, Duke of Guarda: Married with no surviving issue.

• Infante Afonso: Cardinal of the Kingdom.

• Infanta Maria: Died as an infant.

• King Henry: Cardinal of the Kingdom who became King of Portugal.

• Infante Duarte, Duke of Guimarães: Married Isabella of Braganza.

• Infante Antonio: Died as an infant.

Maria was almost constantly pregnant given how many children she had with Manuel. Her constant pregnancies took a serious toll on her health. Maria passed away in Lisbon, Portugal on March 7th, 1517. She is buried at the Jerónimos Monastery in Belém.

Jerónimos Monastery.

Sources:
Ryan, Edward A. “Joan of Castile.” Encyclopædia Britannica. Accessed July 6, 2025. https://www.britannica.com/biography/Joan-queen-of-Castile-and-Aragon.
Bloks, Moniek. “Maria of Aragon - an Overshadowed Queen (Part One).” History of Royal Women, December 6, 2024. https://www.historyofroyalwomen.com/the-year-of-isabella-i-of-castile-2024/the-year-of-isabella-i-of-castile-maria-of-aragon-an-overshadowed-queen-part-one/.