The Force-sensitive former clone trooper X1 founded a splinter faction of the Galactic Empire during the splintering that occurred in the aftermath of Emperor Palpatine's death at the Battle of Endor. The faction was dissolved after his death at the hands of his brother, X2, during the Battle of Mustafar. For a time, X1 used Bast Castle on Vjun as his headquarters.
The faction fielded various military units such as dark troopers, stormtroopers, scout troopers, Wookiee clones, Emperor's Royal Guards, shock troopers, Star Destroyers, TIE/D Defenders, TIE/LN starfighters, TIE/sa bombers, and an Executor-class Star Dreadnought. Along with those, the faction also used battle droids left over from Gizor Dellso's army, such as B2 super battle droids, droidekas, IG-100 MagnaGuards, engineer battle droids, and battle droid assassins in order to have more firepower. The faction also did cloning experiments on Dathomir and had cloning facilities on Mustafar in order to create X1's clone army. On Dathomir, the faction deployed a saboteur.
X1, a former clone trooper turned Sith created out of the DNA of the Jedi Knight Falon Grey, created his own faction following the death of Emperor Palpatine at the Battle of Endor in 4 ABY, during the power vacuum that resulted from his demise. His faction, which sought to create a new Galactic Empire with X1 as their ruler, used Bast Castle on Vjun as their headquarters. X1's forces engaged the New Republic during several battles, including the Battle of Mustafar. However, X1 was slain by his brother X2 during the engagement on Mustafar, and the Imperial splinter faction ceased to exist.
X1's faction appeared in the game Star Wars Battlefront: Elite Squadron. The name of this article is conjectural, as any Imperial forces after the Battle of Endor seen in the game were primarily identified as the "Empire" or "Imperial Remnant".