The history of horror films was described by author Siegbert Solomon Prawer as difficult to read as a linear path, with the genre changing through the decades, based on the state of cinema, audience tastes and contemporary world events.
Films before the 1930s, such as early German expressionist cinema and trick films, have been retrospectively described as horror films, since the genre did not become codified until the release of Dracula (1931). Dracula was a box office success, leading Universal and several other American film studios to develop and popularise horror films well into the 1940s. By the 1950s, horror was often made with science fiction themes, and towards the end of the decade horror was a more common genre of international productions.
