Sometime around the Battle of Hoth, the Nationalists revolted against Imperial rule. They were able to contact the Rebel Alliance, which provided significant military support under the command of General Tyr Taskeen.
After seizing control of, at a minimum, the capital and surrounding countryside, the Nationalists and Rebels opened a dialogue. Five Rebel diplomats, including Luke Skywalker, began negotiations with the Abridon Government Council for Abridon's entry into the Alliance.
These negotiations were interrupted three days after the battle had ended, when Imperial forces led by the Imperial-class Star Destroyer Inquisitor arrived in the system to retake Abridon, sparking the Massacre on Abridon.
- The Complete Star Wars Encyclopedia, Vol. I