Roger Ebert got the best line, when he said that "'The Leopard' was written by the only man who could have written it, directed by the only man who could have directed it, and stars the only man who could have played its title character." That director was Luchino Visconti, who was born into nobility; that writer was Giuseppe Tomasi di Lampedusa, author of the book on which the film is based ... he, too, was born into nobility. That actor was Burt Lancaster, and he might seem an odd fit ... Visconti didn't want him at first. But once you've seen The Leopard, you won't be able to see anyone else but Lancaster in the role.
The Leopard takes place in Sicily around 1860. It helps to know something of the history of the time, but I think you can pick it up after the fact. The themes are easy to ascertain, and the film's greatness comes from how it works those themes: the gradual fading of the nobility, the rise of the nouveau riche, the meaning of rebellion. Much has been made of Visconti's family tree, as well as his Marxism ... it's an odd blend. It allows Visconti (and Tomasi ... it's apparently hard to tell where the book ends and the movie begins) to see all sides of the story. But ultimately, this is a movie about a prince, and we see events through the eyes of that prince as played by Lancaster. This is a prince who sees what is coming, who doesn't even object too much, but largely because he thinks when everything is settled, nothing will have changed. As the prince's nephew (Alain Delon) says and the Prince later restates, "If we want things to stay as they are, things will have to change." In the end, the nephew does want things to change, and the prince is aware that things will not necessarily stay as they were. It isn't played as tragedy (and certainly not as triumph), but the Prince at the end of the film is not the Prince when we first meet him, and we feel for him, no matter what our politics might be, because Lancaster is so great, because Visconti/Tomasi want us to feel as the Prince feels.
Whatever their differences at the beginning of the making of the film, by its finish, Visconti knew what he had. "The Prince in 'The Leopard' was a very complex character -- at times autocratic, rude, strong -- at times romantic, good, understanding -- and sometimes even stupid, and above all, mysterious. Burt is all these things too. Sometimes I think Burt is the most perfectly mysterious man I have ever met in my life."
The Leopard was butchered on its U.S. release ... half an hour was cut, making much of the narrative unintelligible. It was also dubbed into English, which was convenient in the case of Lancaster, who did his own voice on the dubbed version (he is great with someone else's Italian coming out of his mouth in the original, though). It didn't play in America in its original form for 20 years. Now everyone knows it is a classic.
It's a bit unfair to single out one set piece in a three-hour movie that is always gorgeous and interesting. But the ball that takes up most of the last third of the film is stunning, and will always be the first thing people comment on. All of the movie's themes are present in that long scene, and Lancaster is especially brilliant.
I've gone on about Burt Lancaster, because he's great and because he's a favorite. But I'd also note the casting of Alain Delon and Claudia Cardinale, two of the most beautiful actors in the world at the time. #74 on the They Shoot Pictures, Don't They list of the top 1000 films of all time.
For more Lancaster, check out Sweet Smell of Success and From Here to Eternity. Delon is seen to good advantage in Le Samouraï, and Cardinale is one of the best things about Once Upon a Time in the West.