It is one of the most beloved (and haunting) quotes of Obi-wan Kenobi in Star Wars: Episode IV: A New Hope, and quickly gave the viewer a hint of the size and scope of the galactic empire in the film. The complete quote goes like this:
For over a thousand generations, the Jedi Knights were the guardians of peace and justice in the Old Republic. Before the dark times…before the Empire.
Dark Horse Comics based several entire comic book series on this single quote. And then game developer, Bioware, based a video game on the comics. And then Dark Horse made a new comic series based on the video game. And THEN (pant, pant!) the developers made another video game–well, not based entirely on the new comic series, but the story is convoluted (in a fun way) nonetheless.
Long before there was a massively multiplayer online game (MMOG) called Star Wars: The Old Republic (BioWare/EA), there was a Dark Horse comic book series titled Knights of the Old Republic which ran for 50 issues. I collected this series sequentially starting at issue #10 and then picked up the back issues while finishing the series in 2009 when it concluded.
The quality of the artwork is quite good, although the storyline began to drag a bit at times–and it suffered a bit from too many distracting story arcs without any main plot connecting them. There are many unresolved stories in this series that are mostly resolved by the end, such as Jarael’s past and the eventual resolution of Zayne and his former master (or will he help the sith return to power after all?).
If you are a huge fan of The Old Republic and want to read the entire 50-issue series to get even more back story, then I recommend the trade paperbacks (graphic novels), released as 10 volumes encompassing 5 comic issues each. The first collection, with issues #1-5, is called Commencement. This is a good way to get the entire series without having to search far and wide for the individual comics.
The comic tie-in with the video game is not as strong as you might expect. There is mention of Revan and some characters appear, but aside from a few minor differences the time frame is not much different from the future Star Wars universe that fans know and love, featuring Luke Skywalker and Darth Vader (4000 years after the events in this series). If only the real world were as stable.
Dark Horse did a good job with KoTOR, a good series with a varying mix of writers and artists, some better than others. The main complaint I have with this series is that it was based too much on the video game rather than the original Dark Horse series from which is was derived–Tales of the Jedi. That series introduced the world to The Old Republic and is a fascinating tale, originally told in a series of 5 comic issues, now available as a graphic novel.
If you want to get the entire back-story of The Old Republic (the MMOG) and the KoTOR video game series that preceded it, then I highly recommend the Omnibus of Tales of the Jedi, parts 1 and 2 (each ~300 pages in length, all glossy prints!). You will find a lot of familiar themes and places here that are featured in the MMOG, since these two resources were used by the team while designing the game–it’s characters, planets, locations, and quests.