Josef Grunger

Josef Grunger was a Grand Admiral in the Imperial Starfleet. Possibly a native of Alderaan, he was one of the original twelve Grand Admirals, elevated by the Emperor two years before the Battle of Yavin.

Biography
Grunger was neither a loyal nor a subtle man. While Grand Admiral Miltin Takel was making preparations aboard Death Star II, Grunger was aiding Takel's second in command with patrol of the planet Gargon due to reports of "albino-skinned marauders." After learning of the debacle at Endor, Grunger immediately disabled the other officer's vessel. He seized Gargon, an important spice producer, and Grunger's reputation and prowess drew alienated and ambitious ships by the dozens; within a year of setting himself up as a Warlord, Grunger had a fleet of 30 Star Destroyers, 60 Strike cruisers, 100 Carrack cruisers, "various other vessels", and Admiral Roek's Super Star Destroyer Aggressor.

After his coup, Ysanne Isard ordered Grand Admiral Takel to recover his lost holdings and punish Grunger for his rebellion; Takel failed, earning himself a sure death sentence, but events intervened, and he met his end rather at the hands of the pretender to the Imperial Throne, Trioculus. After Trioculus and the Central Committee of Grand Moffs came tumbling down, Grunger re-proclaimed himself the new Emperor (he had previously attempted to be seated as Emperor, but Trioculus' initial success forced Grunger to pledge his loyalty to Trioculus, contingent on his receiving the blessing of the pseudo-Kadann; the quest for that blessing eventually undid Trioculus.) and began securing systems in the Core, preparing for a move on Imperial Center (better known as Coruscant). But first, he had to capture the strategically placed Corellian system and its shipyards. The system had already been unified and pacified by Grand Admiral Danetta Pitta, who was loathe to surrender the system without a fight. In the Battle of Tralus, named after the Corellian planet nearest the engagement, Pitta's fleet, led by a torpedo sphere that Pitta had acquired, utterly devastated Grunger's armada. In fury and desperation, Grunger ordered the Aggressor to ram the torpedo sphere. The ensuing destruction killed both Grand Admirals, and both war engines. This, incidentally, marked only the second time ever that two Grand Admirals engaged in battle.

The Aggressor mystery
The Aggressor would later apparently re-appear. Ysanne Isard, during her preparations for yielding Coruscant to the New Republic, dispatched a Super Star Destroyer to the world of Borleias to convince the genius scientist Evir Derricote to come to Coruscant and develop the Krytos Plague. An agent of Isard's, Kirtan Loor, was going to Coruscant at the same time, aboard a shuttle that claimed to be attached to the SSD Aggressor (which had been destroyed a year prior, at the Battle of Tralus; Grunger, along with the Aggressor had been renegade for two years at that point) when he was delayed; the implication being that it was the Aggressor which had gone to Borleias. The mystery of which vessel had been renamed and under Isard's control at the time was only resolved when it was discovered that, of the known SSDs, all but the Whelm was either destroyed, not-yet built, or not under Isard's control; and the Whelm was the command ship for Azure Hammer Command. It answered to Grand Admiral Teshik prior to the fall of the Emperor, but Teshik was captured by the Rebel Alliance shortly few hours after the Battle of Endor and sentenced to death. Azure Hammer Command was responsible for defending a significant and important section of the Core Worlds, including Coruscant, and command of this fleet would have defaulted to the governing body of the Empire. It is highly likely that command eventually would have been passed on to Isard when she took the role of Stewardess of the Empire. While this fits, it does not account for why Isard did not command the Whelm in addition to the Lusankya when she took over Thyferra and battled Rogue Squadron.