This is the first biography of Barbara of Cilli (1392-1451), Hungarian, Roman-German and Bohemian queen through her marriage to King and later Emperor Sigismund of Luxembourg (1368-1437). While Emperor Sigismund has enjoyed substantial historical attention, Barbara has remained in his shadow, despite her significant political, economic, and cultural influence.

Barbara’s image is still preserved today as the "Black Queen" or the "German Messalina". She has been transformed into a mystical or even demonic figure in folklore – a prime example of the creation and functioning of historical stereotypes – yet as a historical figure she emerges as an influential and exceptional queen.