Combine

In the years before the Empire, The Combine was a militant planetary security force that wished to take over the Galactic Senate. The lacked the galaxy-spanning power of the later Galactic Empire, but had very similar troops, ships, agents and officers.

Behind the scenes
The Combine was created as an antagonistic organization, and used as an example of how to adapt a Wizards of the Coast adventure to any era or situation by changing the story details, and leaving the underlying mechanics and statistics in place.