Documentaries embody the adage that the truth is stranger than fiction. They shine a torch into the darkest corners of the earth and tell the stories of extraordinary people; both the famous and the forgotten. The invention of home video (and, more recently, the camera phone) has effectively made directors and documentarians of us all. But let's start at the beginning. In 1896, the Lumière brothers wowed the world with their L'arrivée d'un train en gare de La Ciotat, a silent, fifty-second film of a train leaving a platform. There's the tale (perhaps apocryphal) of the audience at its first public screening frantically trying to escape the train racing through the screen towards them. The power of film, and indeed the documentary, was unleashed. Considered the first feature-length example of the genre, Robert J. Flaherty's Nanook of the North (1922) captured Inuk Nanook and his family living, trading and hunting in the Arctic Circle, but Flaherty also broke new ground by bending the rules. He had Inuk use spears for the hunting scenes, rather than the rifles used at that time, to create the illusion of a bygone era. Further, he cast a member of the production team to portray Inuk's "wife". Such staging of events was met with considerable controversy, as the documentary was no longer seen as quite the record of authenticity we had been led to believe, but the documentary as weapon, now there was an idea. Following the evolution of the above two titles, we find that truth plus manipulation equals propaganda, the most (in)famous example of which must surely be Leni Riefenstahl's Triumph of the Will (1935). Commissioned by Hitler, the film features a number of speeches from the Nazi Party Congress in Nuremberg and was a key tool in promoting both the Party and the future of Germany. A masterpiece, if viewed for its mechanics rather than its message. When the documentary fell into the hands of such experimental filmmakers as Andy Warhol, it became an endurance test, though, of course, this was the trickster's intention. Having already filmed Sleep (1963), which consisted of five uninterrupted hours of his friend, the poet John Giorno, sleeping, Warhol increased the scale - and running time - the following year for Empire: slow-motion footage of the Empire State building one July night. Although six and a half hours of real time were recorded, the final product was projected at 24 frames per second, making it just over eight hours long. And I thought Cosmopolis dragged. Below are fifty of the greatest documentaries ever produced. Feel free to comment on those included/omitted but please be warned; spoilers abound. Click "Next" to begin...