Mirial first gained fame during the Jedi Civil War, when it aligned itself with Darth Revan. This was seen by most of the Galaxy as acting out for attention, but rather than giving in, they chose to continue ignoring Mirial until it learned its lesson. A few hundred years later, it seemed to have had the desired effect, and Mirial was welcomed ino the Republic. It still didn't get much attention, but it accepted that it was just a cold barren wasteland in the Outer Rim with weird tattoo people. The Trade Federation took an interest in the planet, despite its rather weak trading record, and was able to take complete control of it. Thus, during the Clone Wars, Mirial was aligned with the CIS.