Siege of Inyusu Tor The Siege of Inyusu Tor , also known as the Liberation of Sullust , was a battle that occurred during the Galactic Civil War between the Alliance to Restore the Republic ' s Sixty - First Mobile Infantry and the Galactic Empire on the volcanic planet Sullust . The Siege . The initial siege . Shortly following the Battle of Hoth , the Sixty - First Mobile Infantry initiated Operation Ringbreaker . Devised by the former Governor Everi Chalis it sought to force Imperial redeployments from the shipbuilding world of Kuat by assaulting worlds such as Obumubo , Naator , Xagobah and the asteroid mines of the Kuliquo belt , thus allowing for the them to assault Kuat Drive Yards . When the Sixty - First jumped out of hyperspace a mere half million kilometer s from the planet in an effort to rapidly deploy drop ships to assault the Inyusu Tor mineral processing facility , the attack ultimately went awry the following day when the Imperial Vixus Squadron ambushed their troop transport s and shot down their CR90 corvette the " Thunderstrike " , stranding the company on the planet . Preparing for the assault . Their Captain Hazram Namir decided to reach out to the Sullustan resistance for help but he and his men were attacked when searching in Sullusts capital Pinyumb . The Sullustan resistance leader Nien Nunb rescued Namir and took him back to the other resistance members . Namir realised that the group of four freedom fighters would be of no help but devised a plan that would have the Sixty - First face the coming imperial forces and the Sullustan resistance and willing members of the Cobalt Laborers ' Reformation Front take Pinyumb . Namir went back to Inyusu Tor and faced Chalis who wanted to have the Sixty - First evacuate and continue Operation Ringbreaker . He thwarted her plan and prepared the Sixty - First for the coming attack . Defending the facility . The next three days would result in the blood y siege of Inyusu Tor , initially being in the Empire ' s favour as the " Imperial " - class Star Destroyer " Herald " arrived in the system and the Imperial Army utilized overwhelming force to surround the rebels on the mountain side facility . The Sixty - First had formed three defensive lines with the outer housing various squads hiding behind boulders and slopes , the middle housing a more organised groups of firing squads and the inner housing soldiers and artillery for the All Terrain Scout Transport s the enemy had . The Sullustan resistance finally convinced the Cobalt Laborers ' Reformation Front to rise up in Pinyumb , they were able to mount a fierce resistance . The " Herald " had to face the " Thunderstrike ' s " escort the Braha ' tok - class gunship " Apailana ' s Promise " which had formerly retreated when the Corvette was shot down and come back to help . During the battle , Chalis fled to the nearby city of Pinyumb , killed an Imperial officer , and attempted to escape the planet in a shuttle . Before she was able to leave the atmosphere , the " Herald " locked onto the shuttle with its tractor beam . After being taken prisoner , Chalis revealed the shuttle had been rigged with ion charges and actives them , dealing major power loss to the Star Destroyer . Unable to power its weapons and maintain altitude , the ship began to drop towards the surface and was forced to leave the system . Without the Star Destroyer ' s help , the Imperials significantly weaker and the Sixty - First ' s lead engineer Vifra and her team used machines donated by the Sullustan resistance to excavate ports for lava to flow towards the ground forces . Being overwhelmed , the Imperial forces were defeated . Aftermath . In the following days more uprisings broke out all over Sullust taking it for the Sixty - First . An interim government would be installed in Pinyumb and heavy losses sustained by the Sixty - First would ultimately cancel Operation Ringbreaker , allowing the company to act as a temporary police force for the Sullustan people . Subsequent pirate broadcasts and intercepted Imperial signals indicated further insurrections across the planet , delaying the inevitable Imperial counterattack . The victory on Sullust ultimately played a key role in the outcome of the Galactic Civil War , as the planet was eventually used as the staging ground for the Alliance Fleet before the Battle of Endor . Some time after the battle , the Empire returned to the planet and reactivated an abandoned weapons factory , in an effort to covertly resupply their dwindling forces . The installation was destroyed by Lando Calrissian and Shriv Suurgav , a veteren of the siege of Inyusu Tor , shortly before the Battle of Jakku .