In 2765 the SLS Quéribus was serving as the flagship of the SLDF Eighth Fleet under the command of Admiral Vicho Nnamani. After the Periphery Uprising began the SLS Quéribus and the rest of the Eighth fleet were deployed forward into the Magistracy of Canopus.
The Quéribus survived both the Periphery Uprising and the conquest of the Rim Worlds Republic, continuing to act as the flagship of Admiral Nnamani throughout. As a part of Operation CHIEFTAIN, General Aleksandr Kerensky's campaign to liberate the Terran Hegemony from it's occupation and rule under Stefan Amaris as the Amaris Empire, Nnamani and the Quéribus led a combined task force based around seventy WarShips tasked with destroying the SDS in the Lone Star system. Launched simultaneously with an attack on Nusakan, this was the first attack by the SLDF against an SDS and the associated drone WarShips.
Nnamani initially tried to use small decoy parties to attack the drone fleets at the two main jump points, tasked with hitting and then running for deep space to try and lure the drones away. This was largely unsuccessful; a few smaller drone ships followed the decoys, but the bulk of the fleets remained in place. The defenses as the zenith point of the Lone Star system alone consisted of sixty-two drone WarShips plus a host of smaller drone fighters and assault ships and two defense stations. Nnamani's task force, formed from elements of the Eighth and Thirteenth Fleets jumped for the zenith point, as did the surviving elements of the decoy squadrons. The SLDF WarShips initially tried luring fighting at range, discovering rapidly that the battle for control of the system was going to be far bloodier than initially hoped; the drones concentrated on launching precision attacks against the SLDF carriers and heavy cruisers while taking advantage of opportunity shots at the smaller escort vessels. Nnamani's ships destroyed the drone fleet, in large part thanks to the heavier guns of his battleships, but a third of the SLDF fleet was lost in the action.
The main SLDF ground force then arrived in system, bringing with it reinforcing WarShips in the form of the escort flotilla assigned to XLIV Corps, bringing the SLDF fleet up to sixty WarShips and more than two hundred DropShips. The fleet burned for Lone Star only to be intercepted two days away from the planet by a second drone fleet, this one consisting of two thirds of the drone forces assigned to the nadir jump point augmented by another twenty drone WarShips from the Lone Star defenses. For a second time the drones launched an attack that involved diving into the heart of the SLDF formation and selectively targeting particular ships; in this case, the targets were the transports, and one of the four Divisions assigned to the planetary assault - the 138th Mechanized Infantry Division - was wiped out in minutes, with the others taking significant losses. Even though the SLDF quickly destroyed the drone fleets. The battle was far from done, however; some forty drone WarShips still lay close to Lone Star itself, augmented by Rim Worlds fighter squadrons.
Nnamani and the Quéribus led the SLDF fleet to the moon of Vespa and engaged in a game of cat and mouse with the drone fleet that lasted for three days as the drones attempted to crush the SLDF fleet while simultaneously remaining close to the defense stations. Nnamani's final attack threw his surviving fleet at a single station, pulling in the entire drone fleet in two waves; Nnamani and the Quéribus were a high priority for the drone ships this time, and the Quéribus was destroyed early in the battle, with Nnamani killed aboard his flagship. Leadership of the remaining naval forces fell to Vice Admiral Noeki Giersson, who assumed command from the bridge of her flagship, the McKenna-class SLS Sovereign Justice. Giersson destroyed the drone fleet and two of the defense stations - the third being captured by SLDF marine boarding parties - enabling the ground forces to begin landing on the 22nd of July 2772.
- Historical: Liberation of Terra Volume 1, p. 47, "Sixth Fleet"
- Historical: Liberation of Terra Volume 1, p. 124-125, "The Battle for Lone Star"