Background
Princess Eugenia of Leuchtenberg was born on 1 April on 20 March 1845 at the Mariinskiy Palace in Saint Petersburg. She was the fourth child and third daughter of Maximilian de Beauharnais, 3rd Duke of Leuchtenberg and his wife Grand Duchess Maria Nikolaevna of Russia.
As the daughter of a Russian grand duchess and an ennobled Russian prince, Eugenia and her siblings were always treated as grand dukes and duchesses, bearing the styles Imperial Highness.