The most successful film of Charlie Chaplin’s career was also the most controversial: in The Great Dictator , Chaplin viciously satirized Hitler before the US entered World War II, and the comedy helped rally a previously war-shy American public. The film was co-directed by Michael Kloft and the great silent film historian Kevin Brownlow (if you haven't seen his series Hollywood , on the silent era, find it and watch it post haste), and it tells the story of how and why Chaplin made The Great Dictator, using previously unseen material shot on the set of the film.