(15, 124 mins) Starring Cillian Murphy, Liam Cunningham, Orla Fitzgerald, Padraic Delaney. Directed by Ken Loach

Ken Loach's Palme d'Or winner is a powerful look at Ireland's struggle for independence in the Twenties and the ensuing civil war that turned brother against brother.

Although a straight-up political film, this is an intelligent look at a complicated, painful and overlooked period of Irish history.

The film centres on the young Damien (Cillian Murphy) who, preparing to leave for London to pursue a career in medicine, has his political consciousness awakened by the shocking and arbitrary acts of violence and intimidation he witnesses around him.

Pledging allegiance to the IRA, Damien joins his brother Teddy (Padriac Delaney) and his fellow countrymen as in a bid to free Ireland.

This struggle for freedom seems to revolve around a series of deadly exchanges and brutal reprisals from both sides. By focusing on Damien, Loach locates the contradictions and upheavals of political struggle and war in a single character.

His initial enthusiasm, which inspires his political career, is soon tempered by the ugly and brutal reality of his experiences as an activist. Soon his idealism brings him into conflict with his brother and he comes to shoot an informer.

Cillian Murphy plays Damien with great sensitivity and vigour as we bear witness to the inner turmoil and torture he carries with him. Facing his own brother in the arena of conflict, he tells him, "I tried not to get into this war, now I can't get out of it."

The impassioned optimism of Damien and his men in the first half of the film changes with the formation of the Irish Free State in 1922, when a peace treaty between Ireland and Britain was signed.

They see it as a sell-out and Damien joins ranks with the dissenters.

In one scene, Damien and his band are imprisoned by their former comrades in the same jail in which they were once held by the British. This ironic twist of fate is a clear comment on the anguish of a once united people, now bitterly divided.

As with many of his other films, Loach remains at the level of the everyday person, as Ireland's struggle for independence and Damien's odyssey are brought to us through a marriage of the personal and the political.

Neither a simple thumbs-up to terrorism or a celebration of the IRA, The Wind that Shakes the Barley is an engaging film that asks what drives men to political violence.

Its rather bleak ending is both a lament and a reminder of the pain and anguish of failed political projects.

A potent and well-deserved Cannes winner.