A Star Destroyer was a dagger-shaped type of capital ship that were used by the Galactic Republic, the Galactic Empire, the First Order, and the Sith Eternal. Notable examples of Star Destroyers include the Imperial-class Star Destroyer and its predecessor the Venator-class Star Destroyer.
According to Everi Chalis, Star Destroyers were the most resource-intensive ships the galaxy had ever seen, and only Kuat possessed shipyards that were capable of supporting and maintaining more than a handful at a time.
The Executor-class Star Dreadnought, also known as the Super-class Star Destroyer, was the largest model of Star Destroyer ever built by the Galactic Empire. It was usually referred to as a Super Star Destroyer, and consisted of the sub-models Executor I-class and Executor II-class. 19,000 meters long, it was used as a command ship and had over 5,000 turbolasers and ion cannons.
The Mega-class Star Dreadnought, also referred to as the Mega-class Star Destroyer, was the capital of the First Order and its Supreme Leader. At 13,000 meters in length and a wingspan of 60,000 meters, the Mega-class was wider than it was longer. The sole example of the model the Supremacy was used by Supreme Leader Snoke and the First Order Navy to attack the Resistance.
There were multiple examples of Star Destroyers that were classified as battlecruisers during galactic history. The Maelstrom-class battle cruiser was used by the Galactic Republic during the Clone Wars, was primarily mothballed by the Galactic Empire, and at least one example, the Simoom, was used by the Alliance to Restore the Republic. The Maelstrom-class was considered to be a proto-Star Destroyer, and was armed with assault concussion missile launchers, heavy cannons, and other weaponry. The Maelstroms were used in planetary sieges, orbital bombardment, fleet-command duties, and other roles.
The Secutor-class Star Destroyer, also identified as the Secutor-class battlecarrier, was another example of a battlecruiser in the Star Destroyer design family. Being multiple kilometers in length, the Secutor was used as a carrier and command ship by the Galactic Empire. It was possibly the largest starfighter dedicated vessel in the Imperial Navy. The Empire's successor state, the First Order, widely deployed the Resurgent-class Star Destroyer, alternatively designated as the Resurgent-class Battlecruiser, during the Cold War and the First Order-Resistance War. The Resurgent was a 2,915 meter-long warship that featured advanced weaponry and systems.
According to the Anaxes War College System, the Sith Eternal's Xyston-class Star Destroyer, at 2,406 meters, was a battlecruiser. The Xyston was a model of Star Destroyer that was based on an upscaled Imperial I-class design. The Xyston-class possessed heavy weaponry, including the axial superlaser cannon which had the capability of destroying entire planets.
The Republic's Acclamator-class assault ship was a 752 meter-long cruiser that was considered to be a proto-Star Destroyer. Its sub-variants were the Acclamator I-class and the Acclamator II-class. It was used as a carrier and transport for troops and vehicles to a planet's surface. The Venator-class Star Destroyer was a class of cruiser 1,137 meters in length was also referred to as the Republic Attack Cruiser or Jedi cruiser that was considered a proto-Star Destroyer. It consisted of two sub-variants, the Venator I-class and the Venator II-class, and was extensively used by the Galactic Republic during the Clone Wars and by the early Galactic Empire.
The successor of the Venator-class, the 1,600 meter-long Imperial-class Star Destroyer was also classified as a cruiser. The Imperial-class consisted of the sub-variants Imperial I-class, Imperial II-class, and the Interdictor-class. The Imperial-class became symbols of the Empire's New Order. The Interdictor-class Star Destroyer, also known as the Interdictor-class heavy cruiser, was a class of heavy cruiser that was also part of the Star Destroyer family of ships used by the Empire. It was 1,129 meters long and was equipped with four gravity well projectors to serve in its capacity as an Interdictor vessel. The Onager-class Star Destroyer was also classified as a cruiser class, and was equipped with a superweapon that could destroy targets on the surface of a planet or entire fleets.
Another cruiser, in accordance with the Anaxes War College System, Gladiator-class Star Destroyer was the smallest Star Destroyer in the Empire's arsenal at 600 meters in length. Despite its size, it was regardless heavily armed and was deployed as a patrol ship and escort. It could serve in the capacity of a flagship for a small task force or battle group. The Gladiator I was a sub-variant of the ship.
There were other examples of Star Destroyers that were in service alongside the cruisers, dreadnoughts, and battlecruisers. The Imperator-class Star Destroyer was a large, powerful, and multi-functional warship used by the Republic. The Imperator-class saw limited action, and were soon succeeded by the Imperial-class. The Empire's qaz-class Star Destroyer, armed with multiple batteries, was used by the Empire. The Tector-class Star Destroyer was another example that saw service in the Imperial Navy.
The Victory I-class Star Destroyer deployed by the Republic and subsequent Empire, was another example of the Star Destroyer design. Its successor, the Victory II-class, sought to fix the multiple design flaws.
During the Clone Wars, the Galactic Republic Navy fielded a fleet of Venator-class Star Destroyers. The Venator-class saw action in numerous battles against the Confederacy navy including the Battle of Coruscant. Following the transformation of the Republic into the Galactic Empire, the Republic's Star Destroyers were incorporated into the new Imperial Navy. Aside from the Venator and Imperial-class Star Destroyers, other known models in Imperial service included the Victory and Secutor-class Star Destroyers.
During the rebellion and the Galactic Civil War, Imperial Star Destroyers took part in numerous engagements against the various rebel forces that eventually coalesced into the Alliance to Restore the Republic. Star Destroyers were deployed during the secret mission to Tatooine, Battle of Hoth, and the Battle of Endor.
Following the events at Endor, the Rebel Alliance's successor government, the New Republic, captured and destroyed numerous Star Destroyers in several engagements including the Battle of Theed, the Rebellion on Akiva, the Battle for Kuat Drive Yards, and the Liberation of Kashyyyk. By 5 ABY, Grand Admiral Rae Sloane estimated that 75% of the Imperial Star Destroyers before Endor had either been destroyed, captured, or lost in "confirmable if curious ways." While trawling through the archives at the Hall of Imperial Register on Coruscant, Sloane discovered that the remaining 25% had mysteriously disappeared and their purported destruction had been falsified.
Later, Sloane learned that Fleet Admiral Gallius Rax secretly commanded Imperial fleets in the Almagest, the Recluse's Nebula, the Queluhan Nebula, the Ro-Loo Triangle, and the Inamorata. These fleets consisted of hundreds of Star Destroyers and thousands of smaller ships. Following the Attack on Chandrila, Rax ordered the Imperial fleets to assemble above the planet Jakku. Numerous Star Destroyers, including Captain Ciena Ree's starship Inflictor, saw action during the Battle of Jakku, the cataclysmic battle that ended the Galactic Civil War in favor of the New Republic.
Thirty years after the Battle of Endor, the barren surface of Jakku was still littered with the wreckage of countless Star Destroyers. These derelict starships were regularly targeted by scavengers such as Rey. The First Order, a remnant of the Old Empire, was also known to utilize Star Destroyers as part of its fleet, such as the First Order's Resurgent-class Star Destroyers, which were inspired by the dagger-shaped design of the Old Empire's vessels.