The rosebud lips of Johnny Depp in this film are pursed in a strange expression of irony, stupefied entitlement and droll, martyred awareness of the absurdity of which his royal person is the centre: a human candle starting to melt. He plays Louis XV in the decadent court of pre-revolutionary Versailles, purring his lines in French and playing him as the ageing, slow-moving dandy – though Rip Torn was sexier in the same role in Sofia Coppola’s Marie Antoinette. Depp might actually have been better cast as the lead: Madame Jeanne du Barry, the low-born and entrancingly sensual mistress and royal favourite with whom the king was scandalously infatuated at court, permitting her all manner of familiarities and intimacies. Jeanne is in fact played by the movie’s director, Maïwenn, who has written the screenplay with Teddy Lussi-Modeste and Nicolas Livecchi. Mme du Barry is supposed to be a rebel, although apart from causing some flutter among the courtiers with her gender-dissident clothes, and of course by simply existing, she never seriously challenges anything about court life at all. (Like Coppola’s Marie Antoinette, incidentally, this film finishes well before the guillotine finale.) It is a preposterous confection of a movie, like one of the rich sweetmeats being languidly nibbled at court, but very moreish, nonetheless. It is handsomely furnished and costumed with blue-chip character actors in the supporting roles and some wonderful locations and interiors at the Palace of Versailles itself. Maïwenn plays Jeanne as a sexy, smart courtesan who reads books in the bath (did people in those days really bathe wearing a négligé?). Her first important conquest is the Comte du Barry, a fawning sybarite played by Melvil Poupaud, to whose sweet-natured and bookish son Adolphe she takes a platonic shine, tutoring him in philosophy and poetry. Du Barry sees the obvious social advantage in getting his mistress introduced at court to the king, who is now a widower, and while making a stately procession past an array of bowing flunkies at Versailles, Louis is struck by Jeanne’s beauty. He is impressed by the fearless, and yet somehow satirical way she meets his gaze, and curtsies in the way demonstrated by the Duchess of Sussex in the Netflix docuseries. Having been subject to a gruesome gynaecological inspection by the royal doctors, Jeanne is admitted to the kingly presence à deux; things proceed satisfactorily enough (although we are spared a sex scene) and soon they are gigglingly inseparable. This infuriates all the pompous stuffed chemises thereabouts – especially the king’s grownup daughters with the late queen, who are to be the ugly sisters to Jeanne’s Cinderella. But a problem arrives when the Dauphin (Diego Le Fur), later to be Louis XVI, makes his choice of bride: the comely Autrichienne Marie Antoinette (Pauline Pollman), who declines to acknowledge Jeanne at court, perhaps nettled by Jeanne’s wearing white to upstage her at Versailles. With the decline of the king’s health, Jeanne’s powerbase dwindles and calamity looms. The essential silliness of the film is part of its watchability, though perhaps Maïwenn is never quite sure how to handle Depp. Without this spectacular casting – although Depp is certainly good enough for it not to be simply stunt casting – Louis XV would just be an unsexy old guy, the royal sugar daddy, and much more emphasis would be placed on Jeanne’s political strategising. The presence of the preening Depp always insists on more than that – but Louis and Jeanne are not entirely credible as a love story, perhaps because of the cynicism in which they are both complicit and perhaps because the performances are a little opaque. It’s an entertaining spectacle, only partly aware of its own vanity.