Fans of the long-running military sci-fi drama Stargate SG-1 were shocked when the series was abruptly canceled in 2007. The Syfy Channel announced the series’ closure just as SG-1 aired its 200th episode, making it the first cable scripted television show to reach such a milestone. The series, which premiered on Showtime in 1997 before moving to Syfy for the remainder of the series’ run, followed the adventures of SG-1, a military team traveling from Earth to distant planets using a portal called Stargate. Brad Wright and Jonathan Glassner created the show, which served as a sequel to the 1994 film directed by Roland Emmerich. There are several reasons for SG-1‘s cancellation, and here’s what we know about why the series ended with Season 10.