In the world of film collecting, the claim ''find of the century'' may sound an unpardonable exaggeration. But what discovery can equal it?1 Collectors had hailed the discovery of the occasional lost Keystone comedy in which Chaplin played, but nobody had the slightest idea that somewhere in England, somewhere in France, and somewhere in the United States lay three separate treasure troves of silent film which would, for the first time, reveal the working methods of the greatest single figure of the cinema. It was a treasure hunt involving innocence and guile, accident and coincidence. A treasure hunt which took us to Switzerland, France and the United States. The treasure, when it was uncovered, revealed information as precious as the film itself. From the material, we compiled a television series called Unknown Chaplin, three hour-long documentaries produced for Thames Television. Apart from the experience of making the series, we learned so much about Chaplin we could not squeeze into the commentary we decided to preserve it in the form of a book.