Romy Schneider only agreed to reprise the trademark role of her youth as Empress Elisabeth of Austria if the role would avoid all the usual clichés associated with the character and she would be allowed to portray Elisabeth as the cynical and disillusioned woman Elisabeth was known to be historically, though she did concede to put famous diamond decorations in her hair for one short scene.
After playing Elisabeth of Austria in the Sissi trilogy in the fifties, Romy Schneider made clear she didn't want to have anything to do with the Austrian empress anymore, claiming the character ruined her career as an actress because everyone subsequently wanted to see her in romantic roles. She only agreed to appear in Ludwig ou le crépuscule des dieux (1973) as a favor to Luchino Visconti who was a very good friend of hers.
Final part of Luchino Visconti's German Trilogy also including Les Damnés (1969) and Mort à Venise (1971).