The villa of the movie is Villa Olmo on Lake Como. The lake is never visible in the movie, because it's supposed to take place in Rome.
The royal family of the movie was inspired by the royal family of Monaco: king Gustav (Adolfo Celi) is clearly similar to Prince Rainier III, his wife Betsy (Milla Sannoner) is an American like Grace Kelly and also very similar to her for what concerns appearance and outfit, and also their daughter Cristina (Ornella Muti) is modeled on Princess Caroline. The imaginary state of St. Tulipe, from which the family comes from, is also inspired by the Principality of Monaco, in particular by the presence of a casino.
Ornella Muti and Adriano Celentano already starred together in Il bisbetico domato (1980).
Barnaba Cecchini (Adriano Celentano) lives in the same building where La banda degli onesti (1956) was set.