The ladies swoon and the clothes, manners and accomplishments make the man as Kelvin Harrison Jr. goes full matinee idol as “Chevalier” de Saint-Georges in a lovely film that is both immaculate period piece and colorfully imagined biography of a music star of pre-Revolutionary France.

Josephe Bologne was the “bastard” son of a French West Indies plantation owner and his slave who gained fame as a fencer, a musician and composer in the last years of the French court of Louis XVI and Marie Antoinette.

Emmy winning TV producer and director Stephen Williams (“Watchmen”) and screenwriter Stefani Robinson (TV’s “Atlanta”) conjure up a story that’s both amazing and mostly true, tracking the dazzling career of someone whose father’s lone righteous act was recognizing his talent and putting him in an exclusive French boarding school, which gave him entry into the very heights of French society.

“You must be excellent,” the barely fatherly father (Jim High) counsels. “Always excellent. NO one may tear down an excellent Frenchman!”

We see the boy fence and fiddle his way to the top, making his name in both fields and challenging the aged-out-of-boy-wonder Mozart (Joseph Prowen, terrific) to a (fictional) “Devil Went Down to Grenoble” fiddle-off in front of an astounded, palpitating audience of new (mostly female) admirers.

Even Marie Antoinette (Lucy Boynton, a vision) becomes a fan girl and names young Joseph Bologne “Chevalier” du St. Georges.

“What will you do now that the world is yours, Chevalier?”

But he is black, “mulatto,” and there are limits to his professional life and personal prospects. Marry a black woman and he will lose his status. Cast his eyes at the wrong white woman of his station and he will face the wrath of France.

Professionally, he’d love to lead the faded Paris Opera. Personally, he’d love to take up with the beautifully-voiced beauty Marie-Josephine (Samara Weaving) and cast her in his new opera “Ernestine.” Her stern, military man of a husband (Marton Csokas, fearsome as always), won’t have any of that.

And making an aging opera diva (Minnie Driver, in full Kristin Scott Thomas mode) jealous isn’t a smart play.

Harrison — he was B.B. King in the recent “Elvis” movie — brings a playful, debonnair touch to this character, a dandy who loved showing off his talents and his manners in his fancy blue suits.

The film necessarily over-simpliflies and condenses this not-quite-forgotten man ahead-of-his-time’s life. His reunion with his mother (Ronke Adekoluego) is given short shrift, as are his dalliances in the politics of that day. Attempting to have this story climax during the French Revolution is an overreach, leaving the later acts looking malnourished and playing as perfunctory, soap operatic and incomplete. The last third of the film drags accordingly.

But Harrison dazzles in a vehicle in which Robinson and Williams present him as a real life T’Challa, smarter, more accomplished, braver and better in a sword fight than any white man in his world. His story makes a fascinating reminder of all the history we’ve forgotten, or been made to forget, and returns an “erased” figure to his rightful place as one of the celebrated men of his age, someone whose long and complex story would take a mini-series to be done justice.

Rating: PG-13 for thematic content, some strong language, suggestive material and violence

Cast: Kelvin Harrison Jr. Samara Weaving, Lucy Boynton, Ronke Adekoluego, Sian Clifford, Minnie Driver and Marton Csokas.

Credits: Directed by Steven Williams, scripted by Stefani Robinson. A Searchlight release.

Running time: 1:47