Watch The Csardas Princess for Free: How to Stream the Movie Online at 123Movies. . Sylva Varescu is an operetta singer performing Kálmán's Die Czardasfürstin through Europe with great success. Before going to Vienna she meets handsome Prinz Weylerstein and they fall in love. Offered a contract for America, she doubts until she finds out that he is already engaged to a countess.