Star Trek: Deep Space Nine (sometimes abbreviated to ST: DS9 or DS9) is a science fiction television series set in the Star Trek universe. Set in the 24th century from the year 2369 through 2375, it took place on a space station instead of a starship, so as not to have two series with starships at the same time (the starship USS Defiant was introduced in season 3, but the station remained the primary setting for the show). This made continuing story arcs and the appearance of recurring characters much more feasible. The show is noted for its well-developed characters and its original, complex plots. The series depended on darker themes, less physical exploration of space, and (in later seasons) an emphasis on many aspects of war.
It premiered in 1993 and ran for seven seasons, ending in 1999. Rooted in Gene Roddenberry’s Star Trek universe, it was created by Rick Berman and Michael Piller, at the request of Brandon Tartikoff, and produced by Paramount Television. The main writers, in addition to Berman and Piller, included show runner Ira Steven Behr, Robert Hewitt Wolfe, Ronald D. Moore, Peter Allan Fields, Bradley Thompson, David Weddle, Hans Beimler, and René Echevarria.
A spin-off from Star Trek: The Next Generation, DS9 began while its parent series was still on the air, although there were few crossover episodes between the two shows. The station's first appearance in Star Trek: The Next Generation was during the sixth season episode "Birthright" and in addition, two Next Generation characters, Miles O'Brien and (from Season 4 onwards) Worf, became regular members of DS9.