In his iconic 1963 speech, Martin Luther King shared his dream that one day all Americans would be judged not by 'the colour of their skin, but by the content of their character'. While King's words echo down the years, his optimism remains largely unrealised; indeed, it's impossible to watch Selma without drawing uncomfortable parallels with recent incidents in Ferguson and New York. Yet the power of Ava DuVernay's astonishing film comes from its understanding of the limits of King's work as much as its celebration of his achievements.

Selma concentrates on a pivotal moment in King's campaign for equality: the 1965 marches from Selma to Montgomery to demand voting rights for African-Americans. As King (David Oyelowo) comes up against a nervous President Lyndon B Johnson (Tom Wilkinson), the racist Alabama governor George Wallace (Tim Roth) and the brutal local police force, he must fight to retain the courage of his convictions.

Oyelowo is exceptional, inhabiting this great man with humility, grace and the understanding that he is part of a bigger picture. And he's surrounded by a stellar cast, including the tremendous Carmen Ejogo as his inspiring wife Coretta.

The filmmaking is equally as impressive, with DuVernay and debut screenwriter Paul Webb avoiding the pitfalls of lionising or melodrama. This is most strikingly demonstrated in the sequence in which King first attempts to march across the Edmund Pettus Bridge; the resulting violence is shockingly unflinching without being indulgent. It's all beautifully shot by cinematographer Bradford Young (Ain't Them Bodies Saints, A Most Violent Year), who captures both the power of protest and the intimacy of King's quiet introspection.

Presenting King as a vulnerable, fallible man attempting to turn the tide of history, Selma is a resonant, relevant portrait not just of an individual but also of the relentless hypocrisy of racial inequality in a country built on the ideals of freedom and democracy for all. It's an essential piece of cinema.

General release from Fri 6 Feb.

Selma | Official Trailer