As the story opens, Casanova (Heath Ledger) is in trouble for debauching nuns, and the Inquisition is on his trail. (In real life, Giacomo Casanova did indeed seduce a couple of novice nuns, but the Inquisition got on his case for “witchcraft.” He cast horoscopes and claimed other occult knowledge as a tool in his conquests.) He is set free when the seducee refuses to prosecute, evidently a common phenomenon, but the otherwise tolerant Doge of Venice (Tim McInnerny) declares that Casanova must either find a wife to put an end to his (publicly) scandalous ways, or endure banishment from Venice. Casanova picks out a beautiful and sheltered virgin (Natalie Dormer) as his intended. Why her father is so willing for the match to occur is rather a mystery, but he seems to like Casanova. However, shortly after the engagement is agreed upon, Casanova decides that he really loves the tomboy Francesca (whose brother loves the virginal Victoria), and decides to win her instead, meanwhile keeping Victoria on a string as backup. Since Francesca is a militant feminist who reviles the name of Casanova as an abuser of women, and has moreover been betrothed long-distance to a wealthy man who will repair her family’s fortunes, Casanova does the obvious thing. Obvious, that is, if you are in a comedic film: engage in an aggressive campaign to win the woman based on total deceit. Since the film is very light-hearted and clever about how Casanova agilely maintains his ever-complicated web of deception up to the point it all unravels, it is actually a very humorous and enjoyable movie, which builds up to a dramatic conclusion as Casanova once again escapes the gallows. Ledger plays Casanova as one in a long series of likeable movie rogues, and is fun to watch, although he is not very like the real Casanova in any respect. Sienna Miller is a very present-day young woman, which is good for the plot and doesn’t otherwise matter as she’s not supposed to be a historical character. There is a very entertaining supporting cast, including Omid Djalilli as Casanova’s servant, Lena Olin as Francesca’s mother, and Oliver Platt as Francesca’s gross but good-hearted fiancé. And, one cannot leave without mentioning the formidable Jeremy Irons in a rare comic turn as the Inquisitor. (Irons’ resemblance to the late Boris Karloff is quite striking: if there’s ever a Karloff biopic, Irons would be the man--.)
Suprisingly, what sex there is largely hinted at, and nudity implied rather than shown. The language is very chaste, and the violence is all comic.