Over its decade of existence, science fiction TV series Stargate SG-1 developed an extensive and detailed backdrop of diverse characters. Many of the characters are members of alien species discovered while exploring the galaxy through the Stargate, although there are an equal number of characters from offworld human civilizations. While Stargate SG-1, Stargate Atlantis and Stargate Universe are separate shows, they take part in the same fictional universe, so no character is internally show-specific.