The "Sissi" series of films includes the trilogy "Sissi", "The Young Queen" and "The Queen's Fate". As the first film in the series, the film tells the story of Princess Sissi (played by Romy Schneider) and King Franz Joseph of Austria (played by Karlheinz Böhm) meeting and falling in love. Sissi was born in a noble family in Bavaria. She was beautiful and lively. Aunt Sophie planned to arrange for her son, Franz, the heir to the Austrian throne, to be engaged to Sissi's sister Helen at his birthday celebration. Her mother and sister took Sissi to Austria to attend the celebration. She was naughty and sneaked out to fish, but unexpectedly met the handsome King Franz. Sissi's moving smile deeply touched Franz, making him fall in love with the innocent Sissi completely. He went against his mother Sophie's will at all costs and announced that Sissi was his queen at the birthday celebration. Although lovers finally get married, this romantic and innocent love is just facing a test.