On the beautiful blue Danube
The prince of a fictitious land within the Austro-Hungarian empire comes to Vienna to marry a princess of Brabanzi for reasons of state. But neither he nor his betrothed are willing to be pressed by the imperial ministers. As fate will have it, the two happen to meet accidentally, unaware of their true identity. The imperial police, who are supposed to watch over the prince, decide to sponsor the couple. A love story can finally unfold at the ‘Heurige.' And as the lovers decide to break up after a quarrel, the entire population of Vienna joins in to bring about a royal happy end.