Star Trek: The Beginning

Star Trek: The Beginning was a proposed Star Trek interquel film, set in-between the events of the prequel series Star Trek: Enterprise and Star Trek: The Original Series. It was never given an official release date, but would most likely have been produced some time in the late 2000s.

Plot
The storyline was set in the year 2159, and depicted the beginnings of the war between Earth and the Romulan Empire. The main character was Tiberius Chase, who was heavily implied to be an ancestor of Captain James T. Kirk from TOS.

Why It Was Cancelled

 * 1) The Star Trek series as a whole seemed dead and buried in the mid-2000s, as the last film, Star Trek: Nemesis had been a major critical and commercial flop, while the TV series Star Trek: Enterprise, despite a better reaction to the last two seasons, earned very poor viewing figures.
 * 2) Relied too much on the audience knowing the storyline of Enterprise, which would have made the film inaccessible to casual viewers.
 * 3) Some have doubted that Paramount ever really intended to produce the film in the first place, and that they just had the project on their books so they could run down the contract of long-time series producer Rick Berman.

Results

 * 1) Paramount rejected the script in late 2006, dismissed Rick Berman from the series, and instead hired J.J. Abrams to produce a reboot film, eventually resulting in the 2009 film Star Trek.
 * 2) The idea of an interquel between Enterprise and TOS would also be revisited, but in the form of a TV series (and set just before TOS instead of just after Enterprise), Star Trek: Discovery, which debuted in September 2017.