During the first half of this century, motion pictures were often considered disposable once their circulations were over. The recycling of used film and the use of components for war efforts contributed to the loss of many movies, as did the unstable nature of the nitrate film itself. The loss of extant works has created gaps in the national cinematic history of the United States and most European countries. Eighty percent of all Western-made films produced before World War I are considered lost, while 15 percent of the films made from 1930 to 1950 are also missing. Here are descriptions of nearly 1,000 of the lost American and European films produced between 1900 and 1950, featuring the talents of the still famous as well as the now obscure. The films are arranged by country and reveal the remarkably prolific early filmmaking in countries like the Netherlands and Sweden. Each entry includes production information, cast, synopsis, history, and insights from reviews when available. Photographs from these films provide glimpses of what once was. An extensive index is included.