 The film was shot clandestinely in Rome in 1944 during what is known  in History as the Republic of Salò (when Benito Mussolini (qv) was  deposed and the country occupied by the Germans). At that time, all  cinematic activity was transferred North (Venice) but many actors  and technicians refused to go. Some were able to obtain work permits  delivered by the Vatican, enabling them to go about and work in the  Rome completely freely. Those who were not able to get such  documents had no choice but to work clandestinely.