"The Battle of the Somme [the documentary] is without doubt the most important film in the social history of British cinema...

"It was a great test of how realistic an image of the war the British public could bear to see exposed in public.

"At the height of emotion when the soldiers go over the top the cinema orchestra stopped playing, so suddenly in the cinema there was silence. Suddenly you were presented with an empty space and images of British soldiers being killed. You were invited to fill that space with your own emotion. There were numerous accounts of on one occasion a wounded soldier having to be led crying from the film, of a woman's voice shouting out in the silence of the cinema when the music stopped as the soldiers went over the top after the trenches, crying out, 'My God, they're dead.'"