Marie Catherine Sophie de Flavigny was born in Frankfurt am Main, Germany, to a French émigré noble father and a German banking-family mother.
Marie Catherine Sophie de Flavigny was born on December 31, 1805, in Frankfurt am Main, then part of the Holy Roman Empire's successor territories, during her family's exile from revolutionary France. Her father, Alexandre de Flavigny, was a French aristocrat who had fled the Revolution, and her mother, Maria Elisabeth Bethmann, belonged to a wealthy German banking family of the Bethmann Bank.
This dual French-German heritage and cosmopolitan upbringing would prove formative: young Marie was educated in both French aristocratic culture and German Romantic sensibility, fluent in multiple languages, and exposed early to music, literature, and philosophy. She spent part of her childhood in a convent school in Paris, the Sacré-Cœur, which shaped her intellectual discipline even as she would later rebel against the constraints placed on women of her class.
Her birth into this transnational milieu of displaced nobility and mercantile wealth positioned her uniquely between cultures and classes, a liminality that would later inform her identity as a writer, salonnière, and companion to Franz Liszt. Under the pen name Daniel Stern, she would go on to become one of the most significant literary and intellectual women of the French Romantic era, publishing novels, essays, and a major history of the 1848 Revolution.