Nelson MandelaNelson Mandela died quietly at his home in Johannesburg on the evening of 5 December, just as the dignitaries were gathering for the royal premiere of Justin Chadwick's epic account of his extraordinary life. In the darkness of the London cinema, the audience sat, oblivious, and watched a man being slowly, deliberately stitched into history; his rough edges planed down, his achievements set in stone. By the time the credits had rolled and the news was announced, the monument to Mandela had already been built.  Mandela: Long Walk to Freedom is a conservative film about a radical man, a movie so bowed down by the weight of responsibility that it occasionally trudges when you wish it would dance. At various stages of his turbulent life, Mandela inspired fear and loathing, adoration and awe. But Long Walk to Freedom, although made with rigour and intelligence, is largely content to print the legend and tidy the tensions. To misquote John Huston in Chinatown, "Ugly buildings, whores and Nelson Mandela – they all get respectable if they last long enough."  Adapted by William Nicholson from Mandela's 1995 autobiography, the film is at its best in its urgent opening half, when it charts the political education of its subject against a backdrop of hysterical institutionalised racism. Mandela (superbly embodied by the British actor Idris ElbaIdris Elba) starts out as a wily young lawyer, audaciously defending a domestic servant accused of stealing her mistress's knickers. Outraged by the death of a drunk in police custody, he becomes involved in the ANC struggle against apartheid, burning his identity papers and shuttling between safe houses. It is during these moments that the film catches Mandela at his most knotty and raw. He's a militant firebrand, the scourge of the state. Chadwick's movie shows him cheating on his first wife, neglecting his infant son and smoking like a chimney. In the wake of the Sharpeville massacre of 1960Sharpeville massacre of 1960, he embraces armed resistance, blowing up factories and government buildings. "We no longer accept the authority of a state that wages war on its own people," Mandela explains in those fraught, giddy years before the police run him down and his trials begin.  In the dock at Pretoria, Mandela says he is prepared to die for a free and democratic South Africa. Instead, the authorities sentence him to life imprisonment and fly him out to Robben IslandRobben Island where he and his fellow activists are dressed up like boy scouts and ordered to break rocks in the yard. The decades crawl by and the man turns to myth. He finds himself overtaken by his own reputation. He is forced to sit on the sidelines, growing stooped and grey-haired while the struggle continues. When a young activist, Patrick Lekota (Zenzo Ngqobe), is interred on the island, he comes to peer at Mandela through the chain-link fence, like an unimpressed kid visiting an old lion at the zoo.  Elba's central performance is the movie's trump card, and one it employs with abandon, shuffling the other players far down in the deck. Until now we have known Elba as an imposing, granite presence (as brooding Stringer Bell in The WireStringer Bell in The Wire or the stentorian commanding officer in last year's Pacific RimPacific Rim). But his portrayal of Mandela is beautifully limber; a supple, easy performance inside a stiff and formal film. Elba catches Mandela's loose, rolling gait and the lovely, lolloping melody of his speech. It's not his fault that his acting grows rather less compelling the longer the film goes on. By the time Mandela is released from prison, the activist has become the statesman, with all that this entails. He returns to the stage as a vessel of nobility, urging South Africa back from the brink of civil war; preaching peace and reconciliation to both sides. The film touches lightly on the friction his stance causes with his second wife Winnie (robustly played by Naomie Harris)Winnie (robustly played by Naomie Harris), who has now become an active agent in the war against apartheid and is altogether less willing to let bygones be bygones. There is, perhaps, a whole other movie to be made of this conflict, one that narrows the focus and plays the Mandela marriage as a microcosm for the wider political struggle. But Chadwick rushes us through the domestic ructions in his last-gasp push towards his final destination. The drums are thundering, the strings are soaring and our Long Walk to Freedom is just about through.  Is it a redundancy to mention that Chadwick's tone is weighty, verging on the cumbersome, or that the handling is so respectful that it tips towards reverence? These, surely, are the inevitable pitfalls when it comes to tackling a man like Mandela. The prison could not hold him and the biopic can't contain him. His life was too unruly and expansive to be shoehorned into a neat, three-act structure; its implications too far-reaching to be topped and tailed by the credits. Long Walk to Freedom covers the ground with aplomb and then erects a handsome shrine. It gives us the Mandela of history and allows the man to slip free.
A diligent biopic of Nelson Mandela is lifted by a beautifully supple performance from Idris Elba, writes Xan Brooks