Zero Command, established by Admiral Blitzer Harrsk, was a breakaway group from the Galactic Empire situated in the Deep Core.
In 4 ABY, following the Battle of Endor, Imperial Navy Admiral Blitzer Harrsk led a task force into the Deep Core. There, he laid claim to several planets near Kalist VI, creating a protectorate he named "Zero Command." Harrsk declared himself Lord High Admiral and assumed leadership of Zero Command. The warlord subsequently expanded Zero Command's reach, gaining control over numerous worlds in the Southern Core, such as Abregado-rae and Belgaroth.
When the Emperor Palpatine returned in a clone body, Harrsk and Zero Command initially served him. However, they regained independence after Palpatine's subsequent demise. In 12 ABY, Harrsk initiated a recruitment campaign in the remote Atravis sector, which brought Zero Command into conflict with Treuten Teradoc, an Imperial warlord and a leader of the Federated Teradoc Union. Later, Admiral Natasi Daala reunited Zero Command with eleven other warlord territories, forming the United Warlord Fleets, which eventually evolved into the Imperial Remnant.
Lord High Admiral Harrsk had a fleet of Imperial-class Star Destroyers at his disposal, including the heavily modified Shockwave. Furthermore, he commanded a minimum of two Tector-class Star Destroyers along with the battlecruiser Ilthmar's Fist. Moreover, at least two Super Star Destroyers, Dominion and Megador, were being constructed within Deep 3, one of Harrsk's clandestine shipyards. Deep 3 contained numerous robotic TIE starfighters, mines, and stashes of various armaments. These were later retrieved by Admiral Gilad Pellaeon following Harrsk's death.
The majority of Zero Command's ground troops were composed of Stormtroopers.