In Vienna, young Austrian Empress Sissi (Romy Schneider) is fatigued from the pressures of having to hold court. Though happily married to Emperor Franz Joseph (Karlheinz Böhm), Sissi must endure the familial machinations of Franz's mother, Archduchess Sophie (Vilma Degischer). When Sissi contracts a potentially fatal bout of tuberculosis, the ailing empress retreats to the Mediterranean for a much-needed recovery, on advisement of her loving mother, Duchess Ludovika (Magda Schneider).