Incongruous as it may seem, the pleasures of Jane Austen and the horrors of the British slave trade make a surprisingly elegant and emotionally satisfying fit in "Belle," director Amma Asante's biographical drama about how an exceedingly rare member of 18th-century high society, a woman of mixed English and African ancestry, did her part to push the empire one step closer to abolition. On one level a classically Hollywood tale of white aristocrats deigning to help end black suffering, this handsome period piece nonetheless tells a continually fascinating, unusually layered story located at the juncture of three different lines of oppression (race, class, gender), and grounded by a protagonist with one hell of an identity crisis. Slated for a March release by Fox Searchlight, clearly the slavery-conscious distributor of the moment with this and the much harder-hitting "12 Years a Slave" on its docket, "Belle" should have a ball with arthouse audiences and boasts strong crossover potential.

The relative absence of known facts about Dido Elizabeth Belle gave screenwriter Misan Sagay ("Their Eyes Were Watching God") considerable artistic license in framing the young woman's story within the broader historical context of a slave-centered economy slowly entering its death throes. It is 1769 when young Dido (Lauren Julien-Box), the illegitimate daughter of Capt. Sir John Lindsay (Matthew Goode) and an African slave, is sent to live with her aristocratic great-uncle, Lord Mansfield (Tom Wilkinson), the highest chief justice in the land. Lindsay, who loves his daughter and has embraced her without shame, pleads with his relatives to look after her while he returns to his Royal Navy service; Assante and Sagay wring some mild comedy from the first meeting as Lady Mansfield (Emily Watson) processes the shocking news that the girl is black ("a detail you chose not to share with us!").

But to live under the Mansfields' roof is indeed Dido's birthright, and her relatives grudgingly accept her as a member of the family, bestowing on her a strict, demanding kind of love that, even within their own home, is governed by stiff formalities. One of the story's more astonishing details is the fact that Dido is not allowed to dine with her own relations, especially when they are entertaining guests; on such occasions, it is the girl's habit to join the guests after dinner and witness their varying states of shock, amusement and indignation at seeing the rumors of Lord Mansfield's "mulatto" grand-niece confirmed. Yet Dido's is hardly a joyless existence: She and her half-cousin, Lady Elizabeth Murray (Sarah Gadon), are as close as sisters, Elizabeth having also been left in the Mansfields' care since childhood.

The crowdpleasing Austen elements here are unmistakable, from Lady Mansfield's fussy determination to ensure that both her girls are adequately provided for, to the Elizabeth-and-Darcy tension that develops between Dido and John Davinier (Sam Reid), Lord Mansfield's handsome, outspoken legal apprentice. "Belle" is also a Cinderella story of sorts: While Sarah is groomed for her introduction to society and courtship, Dido is initially kept out of sight, not out of malice or jealousy, but rather a desire to shield her and the family from gossip. Yet in one of the drama's many delicious ironies, it is Dido who turns out to have the upper hand as the heiress to her father's fortune, granting her financial stability, a measure of social currency and a freedom to move about in all-white circles that was unheard of for a black woman at the time; by contrast, Sarah has scarcely a penny to her name and must marry well in order to secure her future.

The key fascination of "Belle" lies in its complex portrait of upper-class priorities coming into conflict -- in this case, the historic segregation of blacks and whites, but also the deep-seated conviction that money should ideally marry money. Asante and Sagay prove particularly attentive to the reality that greed tends to trump prejudice, as when the imperious Lady Ashford (Miranda Richardson), upon learning of Dido's deep pockets, grudgingly agrees to let her son Oliver (James Norton) court the girl. Rather less open-minded is Oliver's brother, James, a sneering bigot played by Tom Felton as a sort of distant ancestor to Draco Malfoy.

All this unfolds at a time when the ground is shifting beneath Britain's feet with regard to slavery, a moral abomination that is nonetheless of vital importance to the national economy. Lending the story its necessary historical heft is the Zong massacre of 1781, a notorious incident in which 142 disease-ridden Africans were hurled from a slave ship and drowned so that the owners might claim insurance for their damaged "cargo." The legal case comes before Lord Mansfield, whose decision will have far-reaching implications for the slave trade and the ongoing treatment of blacks as disposable goods rather than as human beings, and Dido and John find themselves bonding as they attempt to persuade the judge to make the right ruling.

What the right ruling is, and whether Lord Mansfield will make it, is of course never in doubt from the standpoint of the enlightened viewer; every passionate speech and argument here feels calculated for maximum impact and expositional clarity, all the way up to a rousing "Lincoln"-style courtroom climax. Like too many prestige productions, "Belle" unfolds not in a truly unsettling present tense, but rather with the reassuring hindsight of history, encouraging audiences to watch from a comfortable 300-year distance and congratulate themselves for their superiority to the various confused and cowardly aristocrats onscreen.

That the film still works as well as it does is due to not only its polished craftsmanship and disarming comedy-of-manners approach, but also its fascinating insights into the conflicted mindset of British society, particularly in response to the poised and exquisite dark-skinned woman who suddenly appears in their midst. For Mbatha-Raw, who has worked primarily in English television, "Belle" does amount to a Hollywood coming-out party of sorts, and the actress makes a captivating heroine; exuding the dignity and restraint of a young woman well accustomed to unequal treatment, she's nonetheless unafraid to let fly a few verbal darts as occasion arises, delivered with a fiery eloquence in the best Austen tradition.

The tender sisterly dynamic between Dido and Elizabeth, whose mutual affection and desire for each other's well-being trumps any sense of rivalry, is one of the film's chief pleasures, and Gadon gives a spirited yet vulnerable performance as a charming young woman whose lot in life is in many ways inferior to that of her disadvantaged cousin. Wilkinson and Watson are superb as Lord and Lady Mansfield, their fussy sense of propriety barely concealing their love for their adopted daughters. Penelope Wilton ("Downton Abbey") is on hand to throw in some comic relief and spinsterish good advice as Lord Mansfield's unmarried sister, and Richardson makes Lady Ashford a bitchy hoot. Only Reid is a bit of a drip as the lawyer who sometimes loses control of his emotions as he gives voice to his noble convictions; he's a character you admire but wish would shut up once in a while.

Asante's first film since her 2004 kitchen-sink debut, "A Way of Life," finds her working in a decidedly different and much more expensive register. The production is firmly ensconced in the tradition of quality, thanks to Ben Smithard's picturesque widescreen lensing, Anushia Nieradzik's beautifully detailed costumes, Rachel Portman's unsubtly emotive score, and a general air of good taste that would seem more stultifying were the material not so intrinsically compelling.


© 2013 Variety Media, LLC, a subsidiary of Penske Business Media; Distributed by Tribune Content Agency, LLC