According to her Wikipedia article, "Maria Antonia of Naples and Sicily (14 December 1784 – 21 May 1806), was the youngest daughter of Ferdinand, King of Naples and Sicily, and Maria Carolina of Austria. As the wife of the future Ferdinand VII of Spain, then heir apparent to the Spanish throne, she held the title of Princess of Asturias..." She was the daughter of Queen Maria Carolina of Naples, named after her mother's favorite sister, and arch-rival of Maria Luisa of Parma.