The single, middle-aged Hungarian countess Irma Sztáray, having rejected marriage and the convent, is forced by her overbearing mother to apply to be handmaiden to the increasingly reclusive Empress Elisabeth of Austria, also known as Sisi.

An extravagant and temperamental woman, Sisi has been separated from her husband for many years and is living in an aristocratic women-only commune in Corfu, Greece.

Irma falls madly in love with the Empress, and as they travel from Corfu to Algiers, Bavaria to England, the two develop a co-dependent bond – though naturally, only as close as Sisi will allow.

On 5 November 2019, Screen International announced that German sales company The Match Factory would handle international sales on Frauke Finsterwalder's upcoming period drama, whose working title was Sisi – Kaiserin Elisabeth (Sisi – Empress Elisabeth in English), and that it would begin shooting in autumn 2020 in Germany, Switzerland, Ireland and Morocco.

[12] It was reported that their screenplay would tell the story of Empress Elisabeth of Austria through the eyes of her lady-in-waiting in a period in which she was surrounded only by other women and separated from her husband for many years.

[12][13] Finsterwalder described it as "a feminist film full of biting dialogue, a gripping drama with elements of deep black comedy.

[15] Ella Rumpf, Stefan Kurt, Angela Winkler, Johannes Krisch, Maresi Riegner and Sophie Rois were also confirmed in the cast.

[7][17] In an interview for Women and Hollywood in February 2023, Finsterwalder described the film as "a somewhat wild reinterpretation of the “Sisi” myth that isn't really bothered by historical facts.

"[10] When Finsterwalder started thinking about "Sisi" as a character, the 2019 documentary Leaving Neverland about Michael Jackson had just been released, and due to her personal experiences, the issue of the notion of grooming was central, and this is how she began the story of Countess Irma.

[25] Susanne Gottlieb of Cineuropa wrote: "Tackling the Sisi story from an entirely new perspective, Frauke Finsterwalder offers a thought-provoking and entertaining glance at the famous empress", "refraining from making her that sweet little girl from the Ernst Marischka films with Romy Schneider, and similarly steering clear of reimagining her as a feminist icon, as recent media projects have done, is a tactic that works wonders for the character.

"[26] In France, Judith Beauvallet of Ecran Large wrote: "The image, for its part, is very pictorial in inspiration, each shot reminiscent of paintings from different periods, from Marie Laurencin to Edward Hopper via Auguste Toulmouche.