The director, Pier Paolo Pasolini, stayed completely faithful to Sade's text, but relocated the story from the France of the 1790s to the last days of Fascist Italy in the mid 1940s. By doing so, he posited that the treatment of the people at the hands of the Fascists was unchanged from the way the people had been used by the old aristocrats in the Days of Kings. In both cases, the people merely existed as sub-human slaves, for the pleasure of the state and the plutocrats, to be the property of the rich, or even to be sent to war to defend the other property of the rich.
For those of you unaware of the historical background, Mussolini was deposed and arrested in July of 1943, after which Italy negotiated an armistice with the Allies. The Germans intervened, taking all of Italy's major cities, and liberating Mussolini, who was then established as Hitler's puppet in a "new" Italy (RSI), which was headquartered in Salò in Northern Italy. This lasted until 1945, when Il Duce was killed. The German-controlled Italy of the 1943-45 period was called the "Republic of Salò".
Many people claim that all of this was predicted by Nostradamus in this quattrain:
Weep, people of Milan, Lucca, Florence.
When your great Duc will climb on the chariot.
To move the seat closer to Venice,
When the Roman columns will be replaced.
The film is in four parts, following a "Circle of Hell" structure loosely patterned after Dante's "Inferno".
1) Young people are rounded up by the Fascists. Some are made into collaborators, others into prisoners. All are transported to Salo, to serve as the slaves of four perverted nobles.
2) Circle of Mania: the young people are used for the carnal pleasure of the nobles.
3) Circle of sh*t: the young people are forced to consume and otherwise engage in contact with various excremental functions, further degrading them and establishing their complete subservience to the nobles.
4) Circle of Blood: the young people are tortured and killed in grisly ways, thus showing that they are not even considered human by their masters, but rather creatures who exist solely for the amusem*nt of the powerful.
This film has been banned and censored for years, and is recognized as one of the most perverted of all time. That's somewhat misleading.
It is an outré film, but it isn't really as shocking as people have made out. There are some shocking elements. The young people are naked all the time, there are many casual rapes, and there is some explicit sh*t-eating. In the final portion, there are some flesh-burnings, a scalping, a tongue removal, and an eye-gouging. It's no date film. On the other hand, the sex is not explicit, in that there are no erections or penetrations or even gynecological camera angles. The only explicit gore is the scalping, which looks realistic. Other than that, you can see much more explicit gore in the Italian cannibal films.
I would not recommend watching this film for titillation. There is sex and violence, as mentioned above, but it is unpleasant, and surrounded by lengthy and tedious speeches, poetry recitations, etc. The film does not come to any kind of a cathartic conclusion, or even much of a conclusion at all.
Although the film manages to be both tedious and grotesque (a deadly combination), Salo is artistic in many ways, and the cinematography is excellent. There are not many outside scenes, but the few that exist are beautiful. The interiors are lighted very effectively, in what seems to be natural light, and the compositions are artful. I would not claim that this film is without artistic merit. Nor would I claim that it is worth watching, unless your curiosity just plain gets the best of you.