The Imperious-class Star Destroyer, also known as the Advanced Star Destroyer, was a designation applied to the Imperial Star Destroyer named Imperious. This vessel was constructed for the Imperial Navy during the period of the Second Imperial Civil War.
The design of the Imperious-class incorporated several exceptionally large thrusters and featured a 'tailfin,' reminiscent of those found on Star Destroyers of the era of the Galactic Republic. The command bridge design of this class bore a strong resemblance to those found on the majority of warships manufactured by Kuat Drive Yards. Additionally, its sloped superstructure had multiple towers of unknown function, arranged in pairs. In comparison to the Pellaeon-class, the Imperious-class was both larger and possessed greater power, while also demonstrating improved efficiency in power regulation. Its enhanced shielding allowed it to withstand the full firepower of the Outer Rim Third Fleet before shield failure, and its armor and weaponry (including gravity mines) allowed it to surpass any vessel within the Imperial Fleet of Darth Krayt's Galactic Empire in terms of firepower. Furthermore, the Imperious-class required a smaller crew to operate. In general terms, its relationship to the Pellaeon-class mirrored that of the Imperial II-class Star Destroyer to the earlier Imperial I-class.
The genesis of the Imperious-class can be traced to Darth Krayt's requirement for a new class of warship capable of overwhelming any warship utilized by the Empire's adversaries. Moff Rulf Yage, the leader of the Imperial Navy, proposed the project, which was then delegated to the engineers and designers at Mon Calamari Shipyards. Their task was to develop a new warship that represented an overall improvement upon the successful Pellaeon-class Star Destroyer. Ironically, the Imperious-class, despite its service to the Empire, was a Mon Calamari design.
A prototype was eventually constructed at the Mon Calamari Shipyards. However, in 137 ABY, prior to its inaugural voyage, it was utilized as bait for Galactic Alliance Admiral Gar Stazi and his remnant forces. Imperial Admiral Dru Valan of the Outer Rim Third Fleet attempted to trap Stazi and his fleet, but Stazi's fleet managed to escape with the Imperious.
Imperial Knights Masters Sigel Dare and Treis Sinde of the Empire-in-exile had previously placed explosives on the ship, designed to detonate upon activation of the weapons systems, well before the Alliance's hijacking. Once Admiral Stazi was informed of the danger, the explosives were disarmed, and discussions of a renewed alliance between the two governments began. Stazi renamed the ship Alliance to symbolize the element most feared by the Sith.
Despite the loss of the prototype, the damage inflicted upon the shipyards responsible for its construction, and their subsequent closure following the Sith's extermination of the Mon Calamari, Krayt issued orders for the construction of additional Imperious-class vessels before his death.
At least one more Imperious-class vessel was deployed. The Darklight was dispatched to subjugate Falleen in 138 ABY. The vessel was lost after Cade Skywalker and Wolf Sazen infiltrated and sabotaged it.