Human-form Replicators begin to conquer the System Lords, but SG-1 finds and adjusts an Ancient weapon to destroy all Replicators throughout the galaxy.
The SGC is brought back into action when the Stargate is revealed to be part of an interplanetary network connecting countless planets.
SG teams are created to help defend Earth against the Goa'uld, who have interstellar pyramid warships and vast armies of Jaffa (hereditary slaves and human incubators to the Goa'uld) at their disposal.
SG-1 and a dozen other SG teams venture to distant planets using an alien portal known as a Stargate, which in the series is housed in a top-secret United States Air Force military base known as Stargate Command (SGC) in the underground Cheyenne Mountain Complex in Colorado Springs, Colorado.
In the first eight seasons, the mission of the SG teams is to explore the galaxy and search for alien technology and allies to defend Earth against the Goa'uld, a snake-like parasitic alien race that takes humans as unwilling hosts.
Meanwhile, rogue agents of a shadowy intelligence agency on Earth, the NID, repeatedly attempt to take control of the Stargate and other alien technology.
Despite Apophis's death in the beginning of Season 5, the Goa'uld Empire remains a major foe in Stargate SG-1 until the end of Season 8.With 214 episodes over ten seasons, Stargate SG-1 had surpassed The X-Files as the longest-running North American science fiction television series, until it was surpassed by the series Smallville in 2011.The story of Stargate SG-1 begins about a year after the events of the feature film, when the United States government learns that an ancient alien device called the Stargate can access a network of such devices on a multitude of planets.When she engages Anubis in an eternal stalemated battle on the Ascended plane to prevent his acting on the mortal plane, the Replicators and most System Lords have already been annihilated and the Jaffa win their freedom from Goa'uld rule.The original SG-1 team disbands after the events of Season 8, but slowly reunites under new team leader Lt Col.The television series was filmed in and around the city of Vancouver, British Columbia, Canada.