The rank of Grand Admiral had only been found in use by the Galactic Empire. Grand Admiral was a powerful and highly influential rank in the Imperial hierarchy, and was outranked only by the Imperial Exeutor/Supreme Commander, Grand Vizier, the Emperor, and the Emperor's numerous lieutenants and Dark Side Elite. The rank was equivalent to Grand General, its Imperial Army counterpart, but only the rank of Grand Admiral had gained a galaxy-wide reputation for instilling fear and dread in the Admiral's opponents, and command and respect in those below him.
Template:Rank plate During the reign of Palpatine, there were originally twelve Grand Admirals whom collectively were known as the Grand Admiral's Council. One such Grand Admiral served as a superior, known as the Chief Naval Officer, or the Chief of Naval Operations, who served as the chief administrator of the Imperial Navy. The Council and the Chief Naval Officer reported directly to the Imperial Military's Commander-in-Chief, the Military Executor/Supreme Commander, who, at Palpatine's time, was none-other than the Dark Lord of the Sith and Palpatine's lieutenant, Darth Vader.
In addition to the original twelve, however, there was a thirteenth Grand Admiral, who would go on to become one of the more famous Grand Admirals: Grand Admiral Thrawn. After the Battle of Endor, in which Grand Admiral Nial Declann would be killed, the Empire erupted into an internal power struggle and the Grand Admirals found themselves splintered, fighting for their own spheres of influence and the title of Emperor, while the newly-born New Republic hunted them down as high-priority targets.
By 5 ABY, only one Grand Admiral remained: Thrawn. However, during the conflict between Wyth Skellheim and Alaric Darkstar for control of the Interim Ruling Council, Thrawn withdrew his fleet to the Unknown Regions, and had yet to return by 15 ABY. Once Bacharan Valak achieved the goal of an Imperial re-unification and was coronated Emperor, he set out to revive the Grand Admiral's Council and restore the Empire and the Imperial Navy to its former glory.
Grand Admirals were appointed by the Emperor and the Emperor alone, and answered directly to the Executor (or in certain cases in whcih the Executor could not be reached, the Emperor), in all matters. The creation of the rank of Grand Admiral two years before the Battle of Yavin was widely recognized as a means to increase the Emperor's direct control of the Imperial Military. However, although all exceptionally gifted officers, the Grand Admirals were not just front-line commanders; rather, they included several technical specialists and theoreticians, enabling them to serve as a leadership cadre for the whole military—and indeed the whole Empire.
All Grand Admirals, upon promotion to the rank, were also given the esteemed and unique position in the Empire known as Warlord, a post held only by a few of the Emperor's most gifted military commanders. This, however, was done away with by Valak, and only Valak's personal and elite military commanders were given the post, such as Jarl Rellik, regardless of their military rank.
The Grand Admirals were visually distinguished from other officers in the Imperial armed forces by their gleaming white uniform, sometimes worn with bullion epaulettes and rank insignia, sometimes without any badge of rank.