Stargate is an adventure military science fiction franchise, initially conceived by Roland Emmerich and Dean Devlin. The first film in the franchise was simply titled Stargate. It was originally released on October 28, 1994, by Metro-Goldwyn-Mayer and Carolco, and became a hit, grossing nearly $200 million (USD) worldwide. Three years later, Brad Wright and Jonathan Glassner created a television series titled Stargate SG-1 as a sequel to the film.
In addition to film and television, the Stargate franchise has expanded into other media, including books, video games, and comic books. These supplements to the film and television series have resulted in significant development of the show’s fictional universe and mythology. In 2008, the films Stargate: The Ark of Truth and Continuum were released direct-to-DVD, which in total grossed over $21 million in Australia. In 2009, the original pilot was re-cut and released as a direct-to-DVD film. In 2002 the franchise’s first animated series, Stargate Infinity, began airing, which holds no canonicity in the franchise despite its Stargate SG-1-inspired plot. In 2004, the TV series Stargate Atlantis was released as a spin off from Stargate SG-1. A third series, Stargate Universe, premiered on October 2, 2009 and was cancelled during its second season, leaving it with an unresolved cliffhanger. Then on April 17, 2011, Stargate producer Brad Wright announced that any plans for the continuation of the franchise had been cancelled indefinitely, ending 17 seasons (354 episodes) of Stargate television production.
On May 29, 2014, Warner Brothers and MGM announced plans for a reboot trilogy. Roland Emmerich, who directed and co-wrote the original film with Dean Devlin, will direct and Devlin will produce
Stargate productions center on the premise of a “Stargate”, a circular device 6.7 metres (22 ft) in diameter that creates a wormhole, enabling instantaneous transportation to another stargate located many light years away from the starting point. Under the control of the United States government, the Stargate discovered on Earth is kept a secret from the public. This allows for storylines to present no contradiction between depicted events and reality, an effect compounded by setting Stargate in the present day and depicting Earth accurately, with any unrealistic technology originating solely from alien civilizations. These extraterrestrial civilizations are typically more pre-industrial than scientifically advanced and are almost always human. Together, this allows for stories dominated by human interaction in Earth-like environments, an unusual feature for a science fiction franchise focused on exploration of other worlds.
In the story, this is explained as being the result of alien interference in Earth’s past—the concept influenced by the ideas of Erich von Däniken. Many ancient mythologies are shown to be the result of aliens who had visited Earth posing as gods by using their technology to give the impression of deification power. While some of these aliens had benign intentions, a race later known in Stargate SG-1 as the “Goa’uld” used Stargates to move slaves from Ancient Egypt to other habitable planets, simultaneously being responsible for the Egyptian religion and culture. Following a successful rebellion by the humans of Egypt, the Goa’uld fled Earth, and the Stargate was buried and forgotten until modern times, when the United States acquired it following an archaeological dig. With the rediscovery of the function of the Stargate, the galaxy becomes a source of knowledge as well as threats, and the attention of the Goa’uld is drawn once more to Earth.
Due to multiple developers working separately and independently on the franchise over the years, the various Stargate productions are not entirely consistent with each other; and while no set of works forms an official canon, the largest following exists for the three live-action series. Through the work of various authors and developers, at least six separate story cycles can be discerned, some of which are continuations of the other ones (either endorsed or unendorsed by their predecessor).