Star Trek: The Original Series (formally called just Star Trek) is the first Star Trek series. The first episode of the show aired on 8 September 1966 on NBC. The show was created by Gene Roddenberry as a "Wagon Train to the Stars". Star Trek was set in the 23rd century and featured the voyages of the starship Enterprise. Star Trek was later informally dubbed The Original Series, or TOS, after several spin-offs aired. The show lasted three seasons until canceled in 1969. When the show aired on TV, it was little-known and rarely watched, but after it was canceled and went into syndication, it exploded in popularity. It featured many themes such as a Utopian society and racial equality. Ten years later, Star Trek: The Motion Picture reunited the cast, aboard a refurbished USS Enterprise, on the big screen. They appeared in five subsequent films, ending with Star Trek VI: The Undiscovered Country in 1991, during production of the spin-off series Star Trek: The Next Generation and shortly before Gene Roddenberry's death.