Ages ago, a race of alien beings only known as The Ancients created a means of intergalactic travel by using a series of stone portals called Stargates. By a person entering a series of symbols, a Stargate on one planet could establish a connection to a Stargate on another world.

Many years later on the planet Earth, a group of humans unlocked the secret of interplanetary travel of the Stargate. After a deadly encounter with a power-hungry alien race called the Goa'uld, the United States Air Force established a military division that specializes in first contact with alien worlds while combatting the Goa'uld and any other hostiles. The primary function of this special group, called the SGC,: to make contact with The Ancients.