The Sith dreadnaught represented a class of warship that was utilized by the Sith Empire during the time of the Great Hyperspace War. Visually, these dreadnaughts bore a resemblance to lanvaroks.
Back in 5000 BBY, two Sith dreadnaughts known as Harbinger and Omen were engaged in mining Lignan ore on a moon orbiting Phaegon III. This ore was intended for use in the upcoming Battle of Kirrek. However, they were ambushed by Jedi Master Relin Druur along with his apprentice, Drev Hassin. Hassin made the ultimate sacrifice, deliberately crashing the Jedi's Infiltrator starfighter directly into the bridge of the Harbinger. This action resulted in the dreadnaught colliding with the Omen just as both ships initiated a jump to hyperspace. Consequently, the Omen crash-landed on the isolated world of Kesh, where the surviving crew members went on to establish the Lost Tribe of Sith. Meanwhile, the Harbinger was forced into an unstable hyperspace tunnel and subsequently traveled through time, arriving in 41.5 ABY. Shortly after its arrival, it was destroyed by Druur.
At some point between 3959 BBY and 3956 BBY, a Zabrak mercenary named Jamoh Hogra, who was aligned with the Galactic Republic, executed a raid on one of these capital ships. After successfully completing his mission and escaping the starship, he became fearful for his safety and acquired a heavily armored and unique suit of battle armor to protect himself from any potential Sith assassins who might be pursuing him.
Around 41.5 ABY, the Lost Tribe of Sith, aided by Ship, a Sith Meditation Sphere, started building a Sith armada. They were successful in repairing the Omen, adding it to their fleet.