Love conquers all in south London filmmaker Amma Asante’s vital true story which tackles Britain’s murky past using one couple’s unbreakable relationship as a filter for the wider struggles.

Admittedly this is no ordinary couple. Passionate, statesman-like David Oyelowo is Seretse Khama, the heir to the throne of modern-day Botswana, who causes a political storm by marrying white English typist Ruth Williams (a stoic Rosamund Pike) in the late 1940s.

The racism and contempt for their union is bad enough on the streets of London but is nothing compared to the fall-out at home – his tribe divided and a vengeful British Government coming to terms with a crumbling post-war Empire and eager to appease apartheid South Africa.

Sam McCurdy’s cinematography makes the film a joy to look at – historic urban London and the natural beauty of Botswana afforded the same affectionate gaze while making it crystal clear just how far apart these cultures are and how ludicrous it is that one should attempt to control the other.

Together the Seretse and Ruth have the strength to stand up to Britain and the worst the nation throws at them, to unite their kingdom and set it on the path towards democratic independence.

Asante was conscious to show the wider political picture through the prism of this extraordinary relationship and manages admirably thanks in part to stirring performances from Oyelowo and Pike, whose defiant silences and quiet dignity speaks almost as loudly as the set pieces such as Seretse addressing a hostile tribe for the first time since his nuptials, which are powerful if not quite a knock--out.

Where the film risks running into soapy melodrama, Guy Hibbert’s script drags us back with its neat plotting that brings disparate strands back together and is punctuated with enough well-placed humour that sharply punctures the ridiculousness of the Brits establishment, embodied throughout by Jack Davenport’s smarmy ambassador Alistair Canning.

A United Kingdom opened the BFI London Film Festival on October 5. It is at cinemas nationwide from November 25.

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