Born to Isabel and Ferdinand, the Catholic Monarchs whose marriage united the realms of Castile and Aragon, Juana "the Mad" (1479–1555) is one of the most infamous but least studied monarchs of the Renaissance. Conventional accounts of Juana portray her as a sullen woman prone to depression, a jealous wife insanely in love with her husband, and an incompetent queen who was deemed by her father, husband, and son, unable to govern herself much less her kingdoms.

But was Juana truly mad or the victim of manipulative family members who desired to rule in her stead? Drawing upon recent scholarship and years of archival research, author Bethany Aram offers a new vision of Juana's life. After the deaths of three relatives directly in line for the throne, Juana became heir to her parents' realms. As queen, Juana worked tirelessly to assure the succession of her son Charles V to the throne and thereby to establish the Habsburg dynasty in the kingdoms that others managed to govern in her name.

In this part biography, part study of royal authority, Aram rightly asserts that Juana was more complicated than her contemporaries and biographers have portrayed her. Not the frail and unstable woman usually depicted, Juana employed pious practices to defend her own interests as well as those of her children. She emerges as a woman of immense importance in Spanish and European history.