Maria Anna of Spain was a Spanish princess born on September 18, 1634. She was the daughter of Philip IV of Spain and Maria Anna of Austria. In 1650, she married her uncle, Leopold I, Holy Roman Emperor, which was a common practice among royal families to strengthen political alliances. Maria Anna became the Empress of the Holy Roman Empire through her marriage. She had several children, including Maria Theresa, who later married Louis XIV of France. Maria Anna's life was marked by her role in the Habsburg dynasty and her contributions to European politics during the 17th century.