Emperor review – adventure trumps accuracy in civil war biopic

“The history of the civil war was written by white men to serve their own agenda. It’s time for a black man to tell his own story.” The narrative emancipation practised by Emperor, though, is questionable, considering that more than a few liberties are taken with the story of Shields “Emperor” Green, the escaped slave who was hanged after storming Harpers Ferry with John Brown in 1859. Sadly, they are not taken with the same revisionist audacity as Quentin Tarantino gave Django Unchained, with whom this shares a producer. Here, rewriting history seems to consist solely of insisting that exciting gunpowder-keg explosions were a daily occurrence in the 19th century.

Dayo Okeniyi plays Green, who snaps and murders his overseer after the latter whips his son for reading a book. Fleeing for his life, he tries to tap into the underground railroad – and is soon dogged by an elite bounty hunter (Ben Robson) chasing the $1,000 price tag on his head. Director Mark Amin keeps Green on a strict action-movie schedule, packing his journey with swamp manhunts, caravan chases and bank robberies. Historical accuracy obviously isn’t the point, and the pursuit is undeniably rousing, if not subtle. Next to the statuesque Okeniyi, almost every white character looks like a raddled Confederate cadaver.

One thing Emperor is sharp on is the pressure on slaves – and former slaves – to pursue their own self-interest at the expense of their peers. “What is more important – freedom for one man or freedom for all man?” asks James Cromwell’s Brown when the less radical abolitionist Frederic Douglass (Harry Lennix) offers Green passage to Canada. More fine-grained attention to the psychological atmosphere of the period could have made this an antebellum The Fugitive, every scene full of fear and desperation. Instead, it’s merely watchable, a low-stakes contribution to the current renaissance of African American film-making.

• Emperor is available on digital platforms from 1 March.