After gondoliers, Marco and Giuseppe, marry their sweethearts Gianetta and Tessa, they are informed that one of them is really the King of Barataria. However, there is a problem - nobody knows which is the King and which is the gondolier. Gianetta and Tessa are delighted with the idea of one of them being Queen, but later discover, to their horror, that the King was married, in babyhood, to somebody else - and that neither of them will be a queen.