The Clash at Swellen involved the Rebel Alliance in an operation designed to seize the Imperial interdictor named Compellor. At the time, the vessel was being serviced and upgraded at the KDY-77 repair yard facility.
The conflict commenced as T-65 X-wing starfighters, piloted by Rogue Squadron, alongside B-wing starfighters from Green Squadron, emerged from hyperspace. They immediately initiated a systematic dismantling of the KDY-77's fixed defensive structures. Avenger Squadron, tasked with safeguarding the interdictor cruiser Compellor during its refit, was surprised within the repair yard's hangar and suffered substantial damage from Rogue Squadron's assault. Following the obliteration of the turbolaser emplacements, Captain Rigell of the Compellor deduced that the Rebel force's true objective was the capture of the interdictor itself. To prevent the Rebels from seizing his ship, Rigell commanded that the Compellor detach from the spacedock and attempt an escape into hyperspace. However, Green Squadron successfully crippled the fleeing interdictor, thereby enabling the assault transport Lomavcek to dock and take control of the Compellor.
At this juncture, both the Victory-class Star Destroyer Inexorable and the Strike-class medium cruiser Ironhand exited realspace in proximity to the battle, forming a coordinated offensive. Adding to the Rebel force's difficulties was the arrival of Assault Gunboats whose primary mission was to eliminate the Lomavcek. Both the Inexorable and the Ironhand deployed TIE/IN interceptors with the goal of engaging the Rebel squadrons. Shortly thereafter, the Lomavcek communicated that the capture of the interdictor was complete. Under orders to deny the Alliance this technology, the Inexorable launched a full squadron of stormtrooper transports carrying proton torpedoes, intending to destroy the Compellor. Rogue Squadron effectively thwarted this plan by intercepting the launched warheads and destroying the transports. After eliminating the transports, the Rebel fighters turned their attention to the Ironhand. They succeeded in destroying it just as the Compellor jumped into hyperspace. With the Compellor safely en route to Mobetta, the remaining Rebel forces initiated a withdrawal.
While the ambush in the Goff system had already demonstrated the Alliance's increasing boldness in the campaign against Task Force Vengeance, the Clash at Swellen represented a pivotal moment. With the capture of the Imperial interdictor Compellor, the Imperial task force was deprived of its ability to unilaterally disrupt hyperspace travel. Recognizing this, Task Force Vengeance would initiate an extensive search operation for the Compellor with the aim of either recapturing or destroying the valuable warship.