The Dread Masters, a group of six exceptionally powerful Human Sith Lords, acted as prophets, generals, and advisors to the Sith Emperor for countless years. They earned their ominous title through their studies of the Phobis devices, ancient artifacts notorious for driving even the most wicked Sith into states of abject terror. This mastery of fear allowed the Dread Masters to obliterate entire Galactic Republic fleets during the Great Galactic War. They had perfected battle meditation to such a degree that they could inflict a terrifying, unexplainable dread upon any Republic cruiser's crew. To maintain secrecy and evade capture, they constantly moved throughout the galaxy aboard an Imperial dreadnaught. However, Jedi Knight Jaric Kaedan, assisted by an elite Republic Special Forces Division team, successfully infiltrated the dreadnaught and apprehended the Dread Masters. The Jedi Order publicly announced their deaths, but in reality, they were secretly imprisoned on Belsavis.
After being freed by agents of the Sith Empire, the Dread Masters rebelled following the Emperor's defeat on Dromund Kaas. They then established their own empire, governed by their Dread Council. Following the death of one of their members on Darvannis, the remaining Masters relocated to their Dread Fortress located on Oricon, where they were ultimately defeated in 3638 BBY. Only Dread Master Calphayus survived the others' downfall, and he was once again taken into Republic custody.

These Sith Lords became known for their power after delving into the mysteries of the Phobis devices. The sheer power contained within these artifacts was known to drive even the most corrupt Sith individuals to madness, consumed by terror. Their command over this newfound power made them valuable allies to the Sith Emperor, whom they served for centuries in various roles, including advisors, generals, and prophets. Records indicate that they spent extended periods in secluded meditation on the planet Dromund Kaas. These periods of isolation were only interrupted when the Emperor required their crucial wisdom or when they were presented with gifts in the form of supplicants. These Sith maintained such close relationships that they became inseparable, and their collective power reached its peak when they worked together in unison. During the Great Galactic War, they actively participated in the conflict against the Galactic Republic, utilizing their abilities to project terror into the hearts of their enemies. This immense power enabled them to decimate entire Republic fleets. To prevent their location from being compromised, the Dread Masters were stationed on an Imperial dreadnaught, allowing them to maintain mobility by traversing the galaxy.
Despite their attempts at secrecy, their dreadnaught was eventually discovered by Jedi Knight [Jaric Kaedan](/article/jaric_kaedan]. Using this information, he led a Republic Special Forces Division team to infiltrate the Sith vessel with the intention of capturing the Dread Masters. As a result, all six Sith were captured by the Republic, although they resisted all interrogation attempts. Nevertheless, the Jedi were able to determine that the Dread Masters were centuries old. Following the successful mission, the Sith dreadnaught was destroyed, and the Republic disseminated false information claiming that the Dread Masters had been killed in the skirmish. It is believed that the Jedi Council hoped this news would deter the Emperor from launching any rescue attempts. However, another reason for keeping the Sith alive was the belief that their knowledge and abilities were too valuable to simply eliminate. Therefore, imprisonment was deemed the only viable option, and the ancient prison on Belsavis was considered the only place capable of containing the Dread Masters' immense power. This was due to the belief that it possessed security measures strong enough to prevent their escape. Consequently, the Dread Masters were imprisoned on Belsavis, where they remained for a significant period after the Great Galactic War. There was a widespread fear that if the Sith Empire ever managed to free the Dread Masters from their confinement, the galaxy would once again tremble before their might.

While imprisoned on Belsavis, the Dread Masters were held in separate cells located in the facility's main levels. However, the proximity of their presence resulted in the immediate deaths of all other prisoners within a quarter-mile radius. This prompted the Republic to relocate them deeper into the facility, specifically to The Tomb. By 3641 BBY, when the Empire discovered Belsavis, they launched an operation to free the imprisoned Sith. However, their actions inadvertently unleashed the Esh-kha, an ancient race originally imprisoned by the Rakata. The Esh-kha seized the imprisoned Dread Masters and transported them to Cave-Under-Tree, where their High Savants began to exploit their power in an attempt to break free from Belsavis. Subsequently, an Imperial Rescue Team successfully freed them, and after regaining their freedom, they sought revenge on those who had held them captive. The Empire provided them with a shuttle, and they returned to Imperial space.
Soon after, they betrayed the Empire and devised a plan to conquer the galaxy for their own purposes. On Denova, they recruited the Trandoshan warlord Kephess to serve as their proxy. Kephess and his mercenary army attempted to seize control of the planet but were ultimately defeated by joint task forces from both the Republic and the Sith Empire. Undeterred, the Dread Masters healed Kephess and traveled to Asation, where they intended to utilize the technology of the hypergate to unleash the Terror From Beyond. However, they were once again defeated.
Around the time of the Asation incident, the Dread Host, the devoted followers of the Dread Masters, attempted to retrieve a Rakatan weapon known as the Aurora Cannon from Section X on Belsavis. Once again, their plans were thwarted, and the cannon was destroyed. By 3639 BBY, the Dread Masters continued to operate as a third party in the ongoing conflict. They dispatched Sith Lord Tagriss to steal several Sith Artifacts from Arcanum. Tagriss successfully acquired the Seeds of Rage and the Darkstaff. Both the Empire and the Republic deployed strike teams to recover the stolen artifacts, and ultimately Tagriss was defeated on Ilum.
Following three consecutive failures, Dread Master Styrak decided to act independently from the other Masters and traveled to Darvannis. There, he gathered various mercenary groups and Hutt Cartel factions to create a force capable of opposing both the Empire and the Republic. By manipulating the minds of some of the mercenaries, Styrak drove them to insanity. Unfortunately for Styrak, the Empire and Republic detected his activities and dispatched strike teams to intervene. After the mercenaries were eliminated, Styrak sent his Dread Guards and his pet kell dragon to engage the strike team before entering combat himself. Despite proving to be a formidable opponent, he was eventually killed. Upon Styrak's death, projections of the remaining Dread Masters appeared and absorbed his power from his lifeless body.
The Empire and the Republic tracked the Dread Masters to the moon of Oricon, where they had established their base of operations. Both factions dispatched teams with the objective of eliminating the Masters permanently. After fighting their way through the Dread Fortress, the strike teams encountered Dread Master Brontes, and after a challenging battle, they triumphed over the powerful Sith sorceress. The strike team then proceeded to the Dread Palace, the center of the Dread Masters' power. Each of the remaining Masters individually attempted to eliminate the strike team, but their efforts were unsuccessful. The strike team eventually reached the throne room, where all four Dread Masters engaged the team simultaneously in a climactic battle. During the fight, the Masters were bewildered by the strength of the strike team and summoned the spirits of Styrak and Brontes in an attempt to even the odds. However, this had little impact on the outcome, and the spirits were defeated. In a final desperate attempt to achieve victory, the remaining four Masters attempted to drain the life force from the members of the strike team. The strike team then killed each Master one by one; they remained in disbelief that they had been defeated.
Calphayus survived the battle and wandered Oricon after the deaths of his fellow Masters, eventually arriving at the Republic Strike team camp. There, he sought to reason with the team, sharing details of his past as a human. He revealed that he had once been married and felt no fear or pain towards his wife or life in general. However, after he and his friends, who would later become the Dread Masters, studied the Phobis devices, they became mentally and physically linked in a web of Terror and Madness, distorting and transforming him into a living embodiment of Madness. Calphayus was now weak, frightened, alone, and searching for hope. The strike team decided to show mercy and allowed him to be cared for and evaluated by the Jedi.

The Dread Masters made their debut in the 2011 video game Star Wars: The Old Republic. Initially, their character models featured helmets and robes that were also available to player characters as wearable armor. However, in 2012, their appearance was updated to include new and unique helmets that were exclusive to the Dread Masters and not accessible to players. By 2014, a variation known as the Crest of the Dread Master became available.
The ultimate objective of the Belsavis story arc for Imperial characters is to free the Dread Masters. Subsequently, they serve as significant antagonists in the post-story content of Star Wars: The Old Republic. Chronologically, their uprising occurs during an interlude between the character story lines and the Rise of the Hutt Cartel.