The Alliance, originally known as the Imperious, was a large, powerful warship built by the Galactic Empire ruled by Darth Krayt. It was the prototype of the Imperious-class Star Destroyer, a Star Destroyer design larger and more powerful than the Pellaeon-class. It was a personal flagship of Galactic Alliance Admiral Gar Stazi.
Darth Krayt, Dark Lord of the Sith and Emperor of the new galactic empire, had made a demand for a new class of warship that could overpower any type of ship used by the Empire's numerous enemies. With this demand, Moff Rulf Yage, the head of the Imperial Navy, proposed the idea of the Imperious-class Star Destroyer, an upgrade of the Pellaeon-class.
The Imperious was constructed in the Mon Calamari Shipyards in 137 ABY, at the time under control of the usurper faction of the Empire. It was one of the largest ships in the Empire, as well as the pride of the Imperial Navy. For its maiden voyage, the Imperious was to be operated by skeleton crews.
Meanwhile, the Galactic Alliance Remnant was one of the major opponents of Krayt's empire. Admiral Gar Stazi, the Alliance's leader, heard of the Imperious, and knew this was something they couldn't pass up. Stazi made plans to steal it, asking his old friend Gial Gahan to assist with it.
But on the day Stazi and his fleet made the attempt, they were trapped. Admiral Dru Valan, an Imperial commander with a personal vendetta against Stazi, had known about Stazi's plans and set up a trap to capture or kill Stazi and destroy his fleet. What Valan didn't know was that Stazi was prepared for the trap, and turned the Imperials' trap against them.
Stazi ordered his fleet to attack the Outer Rim Third Fleet. When Valan ordered a return fire and fire from the shipyards, the shipyards joined the Alliance in firing on the Imperial fleet, having been hacked by Rogue member Monia Gahan. Meanwhile, the Imperious was retaken by the Alliance; the stormtroopers that had seized it were actually Alliance commandos in disguise. Led by Hondo Karr, they piloted the ship away from the shipyards and successfully got it out of the system. After this, the Alliance fleet retreated behind the planet Dac and were able to escape and make it to the rendezvous point. The Imperious was now in the hands of the Galactic Alliance Remnant. They then began the process of bringing its weapon systems online.
The Imperious with the Galactic Alliance Remnant fleet
Stazi appointed the ship as his new flagship, the successor to the Indomitable.
The Alliance, however, was unaware that Roan Fel's Empire-in-exile had sabotaged the Imperious; activation of the ship's weapons would cause the detonation of three series of bombs that would destroy the vessel. However, Monia Gahan and Imperial Knight Sigel Dare were able to warn Admiral Stazi. The bombs were deactivated and Stazi, impressed that Fel's forces were willing to help him, asked Dare to tell Fel that he was willing to once again negotiate an alliance against the Sith. He also renamed the ship the Alliance.
Meanwhile, Darth Krayt was furious that Stazi had escaped with his best ship, and ordered the genocide of the Mon Calamari for two reasons: to punish the Mon Calamari and try to dissuade any further resistance to his empire. However, while this move did cow some systems into line, many more were outraged and allowed ships from their defense fleets to join Stazi's forces. This was presumably intensified with the death of Krayt on Had Abbadon.
As the vessel was properly outfitted for battle, its sides were adorned with the symbol of the Galactic Alliance, in a similar fashion to the Lusankya, when it was used by the New Republic over a hundred years before.
Under the command of Admiral Stazi, the Alliance fought against the Coruscant Third Fleet during the Battle of Ralltiir. However, Stazi and his crew didn't know there was a traitor onboard their ship. The traitor's betrayal led to an assassination attempt on Stazi and an attack by the First Coruscant Task Force. Fortunately, the assassination attempt failed and the Imperial fleet was outmanuevered and forced to retreat. The traitor, despite deeply regreting his actions, was imprisoned and later expected to be court martialed and executed.
The Alliance fighting over Dac.
The Alliance was present over Dac when the Sith poisoned the waters of the ocean planet in an effort to wipe out every living thing—but Admiral Gar Stazi wasn't ready to abandon the native Mon Calamari without an attempt at evacuation.
The Alliance led an attack on the Sith forces stationed in orbit above Dac, which succeeded in driving the Sith into retreat. When the Outer Rim Third Fleet responded, the Alliance once again led the Remnant's attack. While at first the forces were relatively evenly matched, Imperial forces loyal to Roan Fel arrived and helped turn the tide in the Alliance's favor. The Sith retreated once again, and the evacuation continued. But the evacuation only succeeded in rescuing about twenty percent of the planet's 27 billion inhabitants before the poison made it too deadly to continue.
- "Blaster" — Star Wars Insider 106
- Legacy Era Campaign Guide
- The Essential Atlas