Queen Juana of Castile

Queen Juana of Castile (1479 – 1555) Queen of Castile from 1504 and Queen of Aragon from 1516 to her death in 1555. She was the daughter of Queen Isabella I of Castile and King Ferdinand II of Aragon. Juana was married by to the Austrian archduke Philip the Handsome on 20 October 1496. Following the deaths of her elder brother Juan, elder sister Isabella, and nephew Miguel between 1497 and 1500, Juana became the heir presumptive to the crowns of Castile and Aragon. When her mother died in 1504, she became Queen of Castile. In 1506, Juana's husband Philip became king of Castile as husband of the Queen, (Philip I) initiating the rule of the Habsburgs in the Spanish kingdoms. Philip died that same year. Despite being the ruling Queen of Castile, Juana had little effect on national policy during her reign as she was forced out of power first by her husband, then by her father, and then by her son. She was confined, against her will, in the Royal Palace in Tordesillas under the orders of her father, who ruled as regent until his death in 1516, when she inherited his kingdom as well. Catalina de Medrano, together with her husband, Hernando de Sandoval y Rojas, participated in the custody, or care, of Queen Juana in Tordesillas. Her son Charles I became king, and during his reign Juana was nominally co-monarch with Juana, but she remained forcibly confined until her death. Juana died aged 75 in 1555, at which point her son Charles, also the Holy Roman Emperor, became the sole ruler of Castile and Aragon.
(Wikipedia with edits)