Allegiance-class battlecruiser

The external design of the Allegiance-class battlecruiser bore resemblance to the Victory, Procursator and Imperial-class Star Destroyers. However, it surpassed them all in overall size, measuring an impressive 2,200 meters in length. A key difference from the Victory and Imperial lay in the absence of ventral hangar bays. Similar to other hangarless designs, such as the Procursator and Tector-class, the Allegiance seemed reliant on external weaponry alone, with no capacity for carrying starfighters or ground vehicles internally.

In contrast to the Imperial-class, the Allegiance's terraced dorsal superstructure, which enveloped the bridge tower, exhibited a smoother contour. This design choice resulted in enhanced armor protection and minimized exposure of vulnerable inter-plate joints.

The Allegiance-class incorporated turreted gun batteries arranged in a manner analogous to the dorsal turrets found on the Imperial I-class Star Destroyer. However, its larger dimensions allowed for an increased armament, featuring six guns per turret instead of four. Additionally, the vessel was equipped with several cannons positioned along its central axis, mirroring the arrangement seen on Imperial-class models. Furthermore, three similar batteries were situated on either side of the ship.

An armored reactor bulge, a characteristic feature also present on the Imperial and Victory-class Star Destroyers, was visibly located on the ventral side of the Allegiance-class battlecruiser's superstructure. Given its overall scale, this reactor bulge was proportionally larger than those found on its contemporary Star Destroyer counterparts.

The command tower adopted a T-shaped configuration, consistent with the modular designs employed by Kuat Drive Yards for numerous vessels. Its exposed position rendered it susceptible to concentrated enemy fire. The Allegiance's tower incorporated a prominent section that distinguished it from the main structure, reminiscent of the bridge sections on the Imperial II-class Star Destroyer and the Executor-class Star Dreadnought. Geodesic domes, a common feature on contemporary Imperial warships, capped the tower.

By 3 ABY, the Allegiance-class was actively serving within the Imperial Navy. Prior to the Battle of Hoth, a number of these battlecruisers were observed as part of a fleet during a rendezvous with the elite Death Squadron by Captain Firmus Piett and Admiral Kendal Ozzel, the commander of Death Squadron.

Within the Imperial ranks, the Allegiance was commonly referred to as a "Heavy Star Destroyer" and was recognized as embodying the characteristics of a "Star Cruiser" warship. Its considerable size, formidable power, and combat-oriented design led the Republic Navy War College at Anaxes to classify it as a "battlecruiser" according to their warship classification system. While some military historians used the term "Star Cruiser" to denote smaller battlecruiser variants, this distinction was not universally accepted. This categorization sought to differentiate ships like the Allegiance from larger battlecruisers such as the Praetor Mark II-class.

During the reign of the Galactic Empire, at least three vessels of this class underwent maintenance at the expansive Naval Station Validusia, situated within the Validusia system. Located in the Expansion Region, this Imperial facility possessed the capacity to service multiple heavy Imperial warships concurrently, encompassing standard Star Destroyers, battlecruisers like the Allegiance, colossal dreadnoughts, and fleet replenishment vessels.

In the aftermath of the Arms Race campaign, an Allegiance-class battlecruiser received refueling support from an Altor-class replenishment ship during a fleet training exercise, operating alongside an Assertor-class Star Dreadnought.

During the resurgence of Emperor Palpatine, Allegiance-class battlecruisers were deployed across a spectrum of missions. These included serving as escorts for even larger command ships and bolstering the defenses of Palpatine's forces on Byss as components of the Byss Security Zone. They were deployed throughout the Beshqek system, patrolling and monitoring traffic to and from the secluded throne-world, coordinating with Gauntlet Scanner Stations to eliminate any vessels identified as hostile. During its service with the Dark Empire, the Allegiance-class was occasionally misidentified as an "Imperial-class" vessel or a "Super Star Destroyer" by New Republic forces, primarily due to its visual similarities to the Imperial-class Star Destroyers.

At the Battle of Calamari in 10 ABY, the battlecruiser Allegiance functioned as a command and communications ship for the invasion fleet at Dac, relaying images to the command center on Byss. A New Republic task force intercepted these transmissions while traversing hyperspace en route to the system and pinpointed their origin. Upon exiting hyperspace, General Lando Calrissian ordered all vessels, including his flagship, the Emancipator, to open fire. The ensuing barrage decimated the Imperial battlecruiser and its Procursator-class escorts, resulting in their destruction. Subsequently, Calrissian's fleet bypassed the wreckage of the Allegiance and commenced the deployment of airspeeder reinforcements.

Following the Republic's triumph at Dac, two Allegiance battlecruisers accompanied Palpatine's flagship, the dreadnought Eclipse, on its journey to the Cyax system for a confrontation with New Republic leaders. Later, ships of this class participated in the Battle of the Emperor's Citadel, a failed attempt by a Republic strike team to infiltrate Byss and overthrow Palpatine.

Following the Second Galactic Civil War, it is presumed that all Allegiance-class ships had been either destroyed or decommissioned. Both the Galactic Federation of Free Alliances and the Fel Empire shifted their naval focus towards smaller, more agile designs, and the exorbitant maintenance costs associated with Super Star Destroyers rendered them obsolete for major galactic powers.

The Allegiance-class battlecruiser made its debut as the Super Star Destroyer Allegiance in the third issue of the Star Wars: Dark Empire comic series. This comic was written by Tom Veitch, illustrated by Cam Kennedy, and published by Dark Horse Comics on April 21st, 1992.

In the audio drama adaptation of Dark Empire, a vessel is referred to interchangeably as an "Imperial-class destroyer" and a "Super Star Destroyer," with the corresponding comic panel depicting the Allegiance.

The current canonical representation of the design originated from a detailed fan-created 3D model by Ansel Hsiao. Hsiao based his model on the Super Star Destroyer Allegiance from Dark Empire 3. When Lucas Licensing approached Hsiao to provide artwork for The Essential Guide to Warfare, he submitted his own designs, along with their names, in addition to pre-existing models. These names were subsequently recorded in LFL's Holocron continuity database.

Hsiao's use of "heavy" in the class name on his personal gallery was of his own making. He stated that it is not part of the official name that was submitted to the Lucas Licensing continuity database. Jason Fry, in his Tumblr account detailing endnote trivia in The Essential Guide to Warfare, confirmed the official name as Allegiance-class battlecruiser. He also explicitly identified the unnamed ships depicted in various panels of Dark Empire II as being the same as the Allegiance-class battlecruisers. Fry further attributed the designation "Heavy Star Destroyer" as a canonical nickname and affirmed that the class's specifications were officially documented. The ship-class's designation was also upgraded from a Star Destroyer to a battlecruiser due to the implementation of the Anaxes War College System, which was created for The Essential Guide to Warfare. A similar situation occurred with the Bellator-class dreadnought, where its ship designation was changed from Star Battlecruiser to dreadnought.

In addition to Hsiao's artwork in the book, the design is also featured in a painting by Tommy Lee Edwards. This image incorporates a picture from Hsiao's personal gallery, originally titled "Strategic Reserve," which depicts three ships of the class, although only one is fully visible. The third ship is positioned to the right, in close proximity to Firmus Piett and Kendal Ozzel, facing away from the viewer.