The designation Super Star Destroyer, often shortened to SSD, was a general term utilized by both the Galactic Empire and the Alliance to Restore the Republic when referencing several classes of enormous Imperial starships. These vessels were larger than the standard Imperial Star Destroyers, with the Executor-class Star Dreadnought being the most massive.
Around the period of the Battle of Endor, specifically 4 ABY, the Rebel Alliance Intelligence Service approximated that the Empire possessed over a dozen Super Star Destroyers. This count included Darth Vader's flagship, the Executor, along with vessels such as the Annihilator, the Arbitrator, Emperor Palpatine's personal starship, the Eclipse, and the Ravager. However, the actual quantity of these ships was continuously debated. Following the conflict at Endor, Alliance analysts dedicated themselves to deciphering Imperial propaganda and investigating the secret budgets that concealed the late Emperor's clandestine weapons initiatives. Vader's command ship, Executor, met its end during the Battle of Endor when an RZ-1 A-wing interceptor collided with its bridge, resulting in the vessel crashing into the second Death Star.
By 5 ABY, Grand Admiral Rae Sloane, drawing from her examination of Imperial Navy records on Coruscant, estimated that the Empire had thirteen Super Star Destroyers, including Dreadnoughts, actively serving before the second Death Star's destruction. These included Vader's lost flagship, the Executor, and her own command ship, the Ravager, which was under the command of Fleet Admiral Gallius Rax. Through studying the registers, she also ascertained that the Rebel Alliance's successor, known as the New Republic, had seized control of three Super Star Destroyers. In two instances, admirals surrendered their ships along with their crews, while the third was stolen by New Republic forces while it was undergoing repairs in orbit above Kuat.
Sloane also learned that New Republic forces had destroyed five other Super Star Destroyers in battle. This was achieved by exploiting the ships' understaffed crews and limited maneuverability. Grand General Cassio Tagge's former flagship, the Annihilator, was commandeered by pirates under the leadership of Eleodie Maracavanya. Simultaneously, the Arbitrator was obliterated by a gravity well after a faulty hyperspace calculation while attempting to evade New Republic vessels. While the Emperor's flagship, the Eclipse, was reportedly destroyed by the New Republic Defense Fleet, Sloane discovered that the official report contradicted the vessel's black box recording. Consequently, she concluded that the ship had vanished mysteriously.
The Ravager was destroyed during the Battle of Jakku when the New Republic's Starhawk-class battleship, named Concord, successfully employed its potent tractor beam to pull the Super Star Destroyer down onto the surface of Jakku. Meanwhile, Eleodie renamed the Annihilator to Liberty's Misrule, transforming it into the capital of the Sovereign Latitudes of Maracavanya, a pirate nation situated in Wild Space. Seeking to gain favor with the New Republic, Eleodie utilized the Liberty's Misrule to attack three Imperial II-class Star Destroyers as they fled Jakku. Later, Sloane, accompanied by Brendol Hux, Armitage Hux, and Rax's child soldiers, journeyed into the Unknown Regions and met up with the Eclipse in uncharted territories.