Archduchess Elisabeth Marie Henriette Stephanie Gisela of Austria was the only child of Rudolf, Crown Prince of Austria, and Princess Stéphanie of Belgium. Her father was the son and heir apparent of Emperor Franz Joseph I of Austria, and her mother was a daughter of King Leopold II of Belgium. She was known to her family as "Erzsi", a diminutive of her name in Hungarian. Later nicknamed The Red Archduchess, she was famous for becoming a socialist and a member of the Austrian Social Democratic Party.

Rudolf, Crown Prince of Austria was the only son and third child of Emperor Franz Joseph I of Austria and Duchess Elisabeth of Bavaria (Sisi). He was heir apparent to the imperial throne of the Austro-Hungarian Empire from birth. In 1889, he died in a suicide pact with his mistress Mary Vetsera at the Mayerling hunting lodge. The ensuing scandal made international headlines.