The young Bavarian princess Elisabeth, who all call Sissi, goes with her mother and older sister Néné to Austria where Néné will be wed to an emperor named Franz Joseph, Yet unexpectedly Franz runs into Sissi while out fishing and they fall in love.
Sissi is now the empress of Austria and attempts to learn etiquette. While she is busy being empress she also has to deal with her difficult new mother-in-law, while the arch-duchess Sophie is trying to tell the emperor how to rule and also Sissi how to be a mother.
After a wonderful time in Hungary Sissi falls extremely ill and must retreat to a Mediterranean climate to rest. The young empress’ mother takes her from Austria to recover in Madeira.
Munich, 1864: The 18-year-old, idealistic Ludwig II of Bavaria gets crowned as the Kingdom of Bavaria. His first official act is a lavish support for the inspired but indebted composer Richard Wagner, who settles in Munich after Ludwig's request. Ludwig's cabinet cannot understand his support for the arts and is furious about Wagner's expensive lifestyle. Ludwig tries to find a faithful friend in Wagner, whose music he loves, but these hopes get shattered: Behind the King's back, Wagner has an affair with Cosima Wagner, the wife of Wagner's opportunistic conductor Hans von Bülow. In order to avoid a scandal, Wagner has to leave Munich. Ludwig continues to support Wagner and his projects, but he still feels mistrust against him.
Il film tratta della vita di Elisabetta di Baviera, nota come Principessa Sissi, dal 1854, anno delle sue nozze con Francesco Giuseppe I d'Austria, fino al 1867, anno dell'incoronazione degli imperatori austriaci a re e regina d'Ungheria. Si tratta di una coproduzione europea che ha avuto grande successo anche in Austria e Germania dove si temeva un'accoglienza fredda per il fatto che a interpretare l'amata imperatrice fosse un'attrice italiana.
Inmitten politischer Spannungen und Intrigen am Wiener Hof erweist sich die leidenschaftliche Liebe zwischen Elisabeth und Kaiser Franz Joseph als rettender Anker.
Sisi wirft einen neuen Blick auf das Leben einer jungen Frau, die als Kaiserin Geschichte geschrieben hat und als Filmfigur zur Legende wurde. Sie erzählt die Liebesgeschichte von zwei jungen Menschen zwischen persönlichem Verlangen und politischen Zwängen, zwischen Macht und Verletzlichkeit. Auf der einen Seite Elisabeth von Österreich-Ungarn, genannt Sisi, die als "schönste Frau Europas" bekannt war, sich den starren höfischen Gepflogenheiten widersetzte und die Macht ihrer äußeren Erscheinung für sich und ihre Ideale zu nutzen wusste. Auf der anderen Seite Franz Joseph I., der die Last der Krone in persönliche und politische Härte übertrug und in Sisi eine ungewöhnliche Verbündete fand.