The Expanded Universe novels include a storyline that attempts to justify the Empire's actions in the Star Wars universe.
Each "THIS IS NOT HOW THE FORCE WORKS!" Moment
The Star Wars universe is filled with several unique and interesting alien species that populate the galaxy far, far away. The franchise's original trilogy primarily revolved around the conflict between the Empire and the Rebels, with the former being a fascist group that dominated the galaxy for their selfish gain.
Despite being the primary antagonistic force in the original trilogy and several other eras of the film series, the Empire's actions were somewhat whitewashed in the expanded universe's New Jedi Order novels. According to the novels, the Empire supposedly took control of the galaxy to protect it from a force-immune species. But fans don't accept this logic, and here's what they have to say.
The Star Wars universe originally began with the conflict between the Empire and the Rebels. Since its inception by George Lucas, the franchise has featured several unique alien species, with much of the world-building done through the Expanded Universe novels, which are now considered non-canon.