The Battle of Kaliida Nebula, which is also referred to as the Battle of Kaliida Shoals Medcenter, unfolded in the vicinity of the Kaliida Nebula during the period of the Clone Wars. This engagement is particularly remembered due to the destruction of the flagship at that time of Separatist General Grievous, known as the Malevolence. This vessel had been decimating Republic fleets across the Outer Rim because of its Ion cannon, capable of incapacitating an entire Venator-class Star Destroyer with a single discharge. General Anakin Skywalker commanded the battle, leading a group of BTL-B Y-wing starfighter/bombers; after sustaining significant casualties, the squadron shifted their focus from targeting the bridge to directly attacking the ion cannon. The squadron then launched its torpedoes, which inflicted severe damage on the Separatist ship. Following this, three Venator-class Star Destroyers arrived on the scene to assist in completing the destruction.
During the first year of the [Clone Wars](/article/clone_wars], General Grievous was in command of the secret weapon of the Confederacy of Independent Systems, the Malevolence. The Malevolence, a Subjugator-class heavy cruiser starship, was equipped with two mega-ion cannons that, upon firing, could completely disable entire fleets. This left the ships without power for their shields, weaponry, or starfighters, rendering them utterly defenseless against the Malevolence's heavy cannon fire. The Galactic Republic later referred to it as the "Mystery Weapon" because it would appear without warning, obliterate Republic fleets, and eliminate any survivors who attempted to escape using escape pods, thus maintaining its enigmatic status. One such fleet that suffered destruction was the fleet under the command of Jedi Master Plo Koon, which met its demise at the hands of Grievous during a brief incursion within the Abregado system. However, the Galactic Republic eventually uncovered the existence of the Malevolence and its ion cannons after Plo Koon survived the battle with assistance from Jedi Knight Anakin Skywalker and his Padawan Ahsoka Tano. Against the orders of the Jedi Council, they journeyed to the Abregado system, located and rescued their fellow Jedi, and reported the existence of the Malevolence to the Council.
Following its discovery by the Galactic Republic and the destruction of a convoy of medical frigates escorted by a lone Venator-class Star Destroyer close to Naboo, the Separatist Head of State Count Dooku assigned the Malevolence's next target to Grievous: the Republic's secret medical station situated near the Kaliida Nebula. This station was providing care to over sixty thousand wounded clone troopers under the supervision of the Kaminoan doctor Nala Se. Dooku instructed his loyal general to annihilate the station, recognizing that its destruction would shift the war's momentum in favor of the Separatists. Upon learning of the Separatist ambush in the Ryndellia system, Jedi Generals Plo Koon, Anakin Skywalker, and Skywalker's Padawan Ahsoka Tano recalled that their medical station was also located within that system. Suspecting an imminent attack by Grievous, the three Jedi promptly departed for the medical station with a squadron of Y-wing bombers.