Leading man John Gavin called the film a "turkey" saying Sophia Loren playing a princess was "not what she does best.
The film was part of a three-picture deal, which Loren had, under contract with Paramount. It was also a co-production between Paramount and producers Ponti and Girosi. Filming started on 1 June 1959 in Vienna.In part because Loren was at odds with Curtiz's direction, Italian director Vittorio De Sica was hired to reshoot certain scenes with Loren after hours without Curtiz's knowledge.
John Gavin, who had been borrowed from Universal, later recalled, "we were being directed by Michael Curtiz, which sounds so good on paper." Apparently, he soon realized the director was past it.
I said to Sophia [during the shoot], "We're in a terrible picture. He may have been a great director once but he doesn't know what he's doing."
According to Gavin, Sophia had looked worried and asked, "do you really think so?"
Said Gavin, "The next thing I know Vittorio de Sica is turning up on set, at 2:00am every morning to give Sophia a few hours coaching before shooting started. Imagine! Drama classes at that hour! Still, I wouldn't have minded a little help myself. So I asked him and he said 'Don't change a thing. Everything you do is so American.' That sort of left me up in the air without a compass."