During the Galactic Civil War, the Alliance Fleet included the Nautilian, an MC80A Home One Type Heavy Star Cruiser. This vessel was present at the Battle of Endor near Endor, a decisive battle, where the second Death Star completely annihilated it. Later, in 34 ABY, the admirals Gial Ackbar and Ushos O. Statura exchanged notes regarding the Nautilian within the pages of The Rebel Files.
Mon Calamari Shipyards manufactured the Nautilian as an MC80A Home One Type Heavy Star Cruiser. Like the other ships in its class, the Nautilian had a length of 1,300 meters and possessed a formidable arsenal: six tractor beam projectors, twenty-nine turbolaser cannons, and thirty-six ion cannons. Its ten ion engines allowed it to reach speeds of 975 kilometers per hour.
Additionally, it featured a deflector shield generator, a class one hyperdrive, and a hangar bay with capacity for ten squadrons of starfighters.
During the early rebellion against the Galactic Empire, Meeta Cors commanded the Nautilian while it underwent combat refitting at a rebel stardock situated in the Telaris cometary cloud. Originating as a refugee Mon Cala city-ship, the Nautilian was among the initial vessels to complete conversion into a combat-ready state. It followed Admiral Raddus' MC75 Star Cruiser Profundity and Admiral Gial Ackbar's MC80A Home One, despite facing construction challenges, notably after the Ishanna inversion, which impacted its launch.
The Nautilian participated in the Battle of Endor in 4 ABY during the Galactic Civil War as one of several MC80A star cruisers. Its mission, shared with other capital ships, was to establish a secure perimeter around the second Death Star while rebel starfighters attempted to penetrate the incomplete structure and destroy the reactor. The Emperor Palpatine had set a trap, catching the Alliance Fleet by surprise. As the Alliance Fleet engaged the Imperial Navy, the MC80 Star Cruiser Liberty was obliterated by a blast from the second Death Star, revealing its operational status despite its incomplete construction as a battle station.
While Gold Leader General Lando Calrissian discussed moving the rebel fleet closer to the Imperial Star Destroyers with Ackbar, a second blast from the Death Star destroyed the Nautilian. Onboard the Imperial-class Star Destroyer Vigilance, Imperial Security Bureau Colonel Emarr Ottkreg celebrated the Nautilian's destruction. Ultimately, the Rebel Alliance succeeded in deactivating the deflector shield generator protecting the space station, enabling rebel starfighters to destroy the main reactor and, consequently, the second Death Star.
Following the Resistance's recovery of The Rebel Files in 34 ABY, Ackbar annotated a document concerning whether Home One surpassed Cors' Nautilian during combat conversion. Ushos O. Statura affirmed Ackbar's assessment.
The Nautilian made its debut, though unidentified, in the 1983 film, Star Wars: Episode VI Return of the Jedi. Chuck Wendig identified it in his 2016 canon novel, Aftermath: Life Debt.