The memory of the Spanish Infanta Maria Anna of Austria and Empress of the Holy Roman Empire was lost in the endless list of empresses who populated the modern era. None of them reached the fame of the absolutist Empress Maria Theresa, who reigned in the 18th century, and even less so the popularity of the troubled Sissi of the 19th century, who became a legend after her assassination and, especially, through the romanticized and sweetened film versions of her life in the 20th century. Maria Anna led a fascinating life: daughter, sister, aunt, and grandmother to Spanish kings of the 17th century, and mother of the Spanish queen Mariana of Austria. She was the sister-in-law and aunt of French kings Louis XIII and Louis XIV, respectively, and wife and mother of two emperors, Ferdinand III and Leopold I of Germany. But before she was the fiancée of the Prince of Wales Charles Stuart, the future King Charles I of England and Scotland, who traveled incognito to Spain, accompanied only by his father's minister and favorite, the Duke of Buckingham, to meet and win her over. Through the pages of her life parade some of the most unknown yet intriguing members of her family: Prince Baltasar Carlos, Cardinal-Infante Don Fernando, Infante Don Carlos, Queen Isabel of Bourbon... She was also connected to the intellectual elite of Spain's Golden Age: Quevedo, Lope de Vega, Calderón de la Barca; she posed for the greatest painters of the time, Velázquez and Rubens; and led a vibrant life across the courts of Madrid, Vienna, Prague, and Naples. She may even have been the subject of one of the most enigmatic paintings in Spanish art: The Rokeby Venus.