The dreadnought was one of the Galactic Empire's thirteen Super Star Destroyers—a name given to several classes of Imperial capital ships—during the Galactic Civil War. As such, it was equipped with a propulsion system and extensive weapons systems.
Prior to the Battle of Endor in 4 ABY, the dreadnought was one of the thirteen Super Star Destroyers originally in Imperial service. The Empire's defeat at Endor, which saw the death of the Emperor and the destruction of the second Death Star, left the Imperial forces fractured, while the victorious Rebel Alliance transitioned into the New Republic.
After the battle, the dreadnought transmitted tracking data to the Hall of Imperial Register on the Imperial planet Coruscant, allowing for a black box recording of information so the Empire could discern what had happened to the ship in the event it was destroyed, captured, or had surrendered. Indeed, by 5 ABY, the dreadnought was undergoing repairs at the Imperial planet Kuat, when it was captured by the New Republic for use in its fleet.
Later, Imperial Grand Admiral Rae Sloane of the Executor-class Star Dreadnought Ravager visited Coruscant to research Gallius Rax, her mysterious superior. While at the Hall of Imperial Register, Sloane discovered that eleven of the Empire's thirteen Super Star Destroyers, including the dreadnought, had been lost, with the only two remaining being the Ravager and the Eclipse.
The dreadnought was mentioned in Star Wars: The Aftermath Trilogys second novel, Aftermath: Life Debt, which was written by Chuck Wendig and released in 2016.