Stargate SG-1 is a Canadian-American adventure and military science fiction television series and part of Metro-Goldwyn-Mayer's Stargate franchise. The show, created by Brad Wright and Jonathan Glassner, is based on the 1994 feature film Stargate by Dean Devlin and Roland Emmerich. The television series was filmed in and around the city of Vancouver, Canada. In the United States, Showtime broadcast the first five seasons, from 1997 to 2002, and then the series moved to the Sci Fi Channel for its last five seasons, from 2002 to 2007. The final episode premiered on Sky1 in the United Kingdom on March 13, 2007, three months before its United States premiere. With ten seasons and 214 episodes, Stargate SG-1 surpassed The X-Files in 2007 as the longest-running North American science fiction series on television, before being surpassed by Smallville in 2011 with 218 episodes in ten seasons.
The story of Stargate SG-1 begins about a year after the events of the feature film, when the United States government learns that a network of ancient alien devices called Stargates connects a vast multitude of planets within our Milky Way galaxy, facilitating near-instantaneous interstellar travel. Later episodes reveal that this network is capable of spanning not just planets within the Milky Way, but with sufficient power, can provide intergalactic travel as well. Stargate SG-1 chronicles the adventures of the elite special force Air Force squad, SG-1, the flagship team of over two dozen teams from Earth who explore the galaxy and defend Earth against alien threats such as the Goa'uld, Replicators, and later the Ori. The composition of the SG-1 team is stable in the show's first five seasons but changes several times in the remaining seasons. The series expands upon many Ancient Earth mythologies such as Egyptian mythology, Norse mythology, and Arthurian legend.