The Believers, initially dismissed by the Jedi Knights as mere rumors, were in actuality a Sith cult devoted to the dark side of the Force operating on the planet of Cularin. As the Clone Wars progressed, they became a significant threat to the Jedi, with many Jedi succumbing to their influence and joining their ranks. Their base of operations was eventually discovered to be the ancient Almas Sith fortress. Furthermore, they extended their reach to the ruined Almas Academy following its destruction. A distinctive tattoo marked all Believers, depicting the Sith fortress spire on Almas with a broken lightsaber situated at its base.
During the declining years of the Galactic Republic, a Sith-worshipping cult, known as the Believers, began to take shape within the Cularin system. This cult was established by Len Markus, a Human student deeply immersed in the study of Sith magic, who sought to master the ways of the dark side of the Force and challenge the Jedi Order. Their ultimate goal was to usher in a new era for the Sith, the ancient practitioners of the dark side. The cult adopted a decentralized, matrix-like structure, lacking a central authority. One faction of Believers came under the leadership of Gar Granga, a Mon Calamari Dark Jedi. With the assistance of Murk Lundi, a Quermian Sith scholar, the cult expanded its influence across the Cularin system, establishing footholds on the planets of Almas and Cularin, as well as in the cities of Depatar, Elso Magua, Hylios, Tolea Biqua and Varna Biqua situated on the planet Genarius. Shortly after the Battle of Naboo in 32 BBY, the cult's prominence grew. Rumors regarding the Believers' emergence eventually spread throughout the galaxy and reached the Jedi Order, although the Jedi were initially unable to confirm the cult's existence.

Sometime around 31 BBY, within the ancient Almas Sith fortress constructed by Darth Rivan, a Sith Lord, on the planet Almas in the Cularin system, researcher Garvin Delquist unearthed a Sith amulet. This discovery occurred within the Sith structure. The amulet imbued Delquist with Force abilities, corrupting him to the dark side. Following this transformation, he reached out to Gar Granga, establishing an agreement that allowed the Believers to inhabit the fortress. Furthermore, Delquist contacted Alina Impeveri, a Human figure deeply embedded in the Cularin system's criminal network. Impeveri consented to join the Believers, bringing a substantial contingent of pirates who then enlisted in the cult and established their base within the Sith fortress. Delquist rose to lead this combined force of Granga's cultists and Impeveri's pirates, centralizing the cult's power and focusing its activities increasingly on Almas.
The Almas Academy, a training center for Jedi, existed on Almas. Delquist devised a scheme to expel the Jedi from the planet by eradicating the kaluthin, a plant genetically engineered by Darth Rivan to render Almas habitable. Acting on Delquist's directives, Granga and the Gungan Dark Jedi Kosa-Yin Hadu launched a mission to contaminate Almas' aquifers, with the intent to kill the kaluthin. Accompanied by Believer thugs, the Dark Jedi duo established a temporary base atop an Almas hill. From this vantage point, they launched raids on nearby kaluthin farms, poisoning their water supplies with a biological toxin, including an assault on the farm owned by Rashen Sotose, a man. Over a period of three months, the Believers successfully decimated vast areas of kaluthin.
Scientists working at a kaluthin research station on Almas initiated an investigation into the kaluthin die-offs. Hadu and Granga grew concerned that the station posed a threat to their operation, fearing that the researchers might identify the toxins they were using to poison the aquifers. Seeking to neutralize this potential threat, Hadu, Granga, and several other Believers journeyed to Cularin, where they conspired to intercept a supply shipment destined for the research station, aiming to prevent the scientists from conducting their studies. These supplies were scheduled to be transported to Almas by Welrin Maduk, a Duros, aboard the freighter Fool's Paradise. Consequently, the two Dark Jedi, accompanied by other Believers, made their way to the Fool's Paradise's landing bay in the city of Hedrett, intending to hijack the vessel. The Believer party, escorted by a squad of battle droids, approached the Fool's Paradise, preparing to attack Maduk. However, the Heroes of Cularin, a team of freelance agents operating within the Cularin system, observed the threat to Maduk and intervened to rescue him. As the agents neared the Fool's Paradise, Hadu and Granga retreated through a hidden entrance to the hangar, leaving the battle droids and the remaining Believers to confront the agents alone. The agents ultimately defeated the remaining Believers, allowing Maduk to proceed to Almas unharmed.
Hadu returned to Almas, and the Heroes of Cularin launched an inquiry into the kaluthin's demise. Shortly thereafter, a group of Believers, utilizing airspeeders, traveled to a rocky valley on Almas, near a kaluthin farm, where they began dumping barrels of the biological toxin into a natural well. However, the Heroes of Cularin spotted the Believers, confronted them, and seized a datapad that revealed the location of the Believers' encampment. The agents then launched an assault on the camp, engaging Hadu and three of his bodyguards in combat, while the other Believers present in the camp started their airspeeders and fled. Soon a group of Jedi arrived on the scene to support the Heroes of Cularin, and Hadu and his guards were defeated.
In the week preceding the Almas Jedi's annual recital of the tale of the Dark Jedi Kibh Jeen, the Believers executed a drive-by attack on Remembrance Hall, a museum situated in Forard, Almas' capital city. As the museum teemed with tourists, three Human Believers approached the building in an XP-34 landspeeder, hurling a pair of thermal detonators into the hall. The explosions damaged a section of the museum's wall and incinerated a holoplacard created by the Rodian artist Zyk-yadoon. Amidst the ensuing chaos, a Tarasin Believer crawled across the damaged wall, scrawling the words "Death to the Unfaithful" upon it. The Believers then swiftly departed the scene of their crime. Following the attack, Delquist captured the Jedi Padawan Misha Quor-Din in the Almas Wasteland and transported her to the Sith fortress. Delquist harbored romantic feelings for Quor-Din, but he soon realized that the Jedi would never reciprocate his love, and the Believers made plans to sacrifice her.
Around this time, a report on the Believers' activities, authored by IP17 in a format used by the Almas Academy, briefly appeared on every HoloNet news board in the Cularin system. The report suggested that indications of significant dark side Force usage within the cult were exaggerated. It also claimed that the crime lord Nirama was aware of the Believers' actions and that the Believers might be cooperating with the Wyrd, a group of Tarasin Force witches from the planet Cularin. Additionally, the report asserted that the Believers posed a considerable threat to the well-being of the system's inhabitants. Numerous rumors circulated among Cularin's residents regarding the report's origins, with some speculating that the Believers themselves had written it to sow fear.
Following Quor-Din's capture, the Believers dispatched several security teams from the Sith fortress to gather supplies for the cult. A group of Believer pirates boarded a smuggler-operated freighter, murdering the crew and stealing three submersibles that the vessel was carrying. The pirates transported the submersibles to an underground river on Almas and began using them to transport cargo to the Sith fortress via an underwater passage. The Jedi launched multiple search parties to locate Quor-Din, and the Heroes of Cularin formed one such team. These freelance agents investigated the underwater river, engaging a group of Believer pirates in combat before traveling aboard one of the submersibles to the Sith fortress. Upon arrival, the Believers unloading the cargo from the submersibles mistook the agents for fellow cult members and instructed them to unload the craft.
The agents moved through the fortress and watched Gar Granga leading approximately twenty cultists in chants of devotion to the dark side within the fortress's Grand Hall. The agents then confronted and defeated Delquist, Granga, and the Believers D'randq and Sellot Kell, triggering a klaxon that signaled the cultists to retreat from the fortress. In a panic, the Believers attempted to flee the facility, with some trying to escape aboard a skiff. The freelance agents rescued Quor-Din and attempted to depart the fortress aboard another skiff, but they collided with the Believers' skiff and became embroiled in a firefight with a large group of cultists. Jedi Master Lanius Qel-Bertuk, the headmaster of the Almas Academy, and a contingent of Jedi soon arrived at the fortress, leading a brigade of armed troops and storming the facility, causing the remaining Believers to scatter in disarray. Many surviving Believers went into hiding, while numerous cultists were captured by the Jedi. To prevent the Believers from reclaiming the Sith fortress, a Jedi delegation was assigned to maintain a permanent guard over the facility.
A team of Jedi researchers recovered a Sith artifact known as the Pulas from the Sith fortress and attempted to transport it to the Almas Academy for safekeeping. However, the Believers learned of the Jedi's discovery and plotted to steal the Pulas, attacking the researchers en route to the Academy. Despite their efforts, the Believers failed to acquire the artifact. The next day, a group of cultists attempted to break into the Academy in a further attempt to obtain the artifact. Again unsuccessful, the group committed suicide to avoid capture by the Jedi. Recognizing that the Believers' presence on Almas made the Academy an unsuitable location to store the Pulas, Jedi Master Qel-Bertuk assembled a small fleet of starships to transport the artifact to Coruscant, where it could be secured within the Jedi Temple, the headquarters of the Jedi Order. To complicate any Believer attempts to seize the Pulas during its transport to Coruscant, Qel-Bertuk encased the artifact in a box of Mandalorian iron and loaded it onto one of the ships in his fleet, placing decoy boxes on each of the other ships.
As the fleet prepared to depart the Cularin system, a Believer-operated Z-95 Headhunter attacked one of the ships in the Cularin comet cloud, under orders to destroy the vessel but leave enough of it intact for the Believers to search the wreckage for the Pulas. The attack failed, and the Jedi fleet successfully departed the system, traveling to Coruscant. However, Es'Loma, a Tarasin agent of the Wyrd, was serving aboard the ship carrying one of the Mandalorian iron boxes. She incorrectly identified her vessel's cargo as the Pulas itself, when the ship was instead carrying a fragment of the dark-side-imbued floating city Conkesta. Es'Loma contacted a group of Believers based in a bunker in the Coruscant Undercity and orchestrated a plan for the Believers to raid her ship and recover the Mandalorian iron box. After Es'Loma's ship docked with a Coruscant landing platform, a team of black-clad Human Believers, led by the Omwati Bleth Fahr, assaulted the crew of Es'Loma's ship. Nysis Belzara, a Bothan Jedi Knight sent to escort the ship's crew to a safe house, arrived on the scene. Fahr and his accomplices killed the Jedi and seized the box containing the fragment of Conkesta.
The Believers fled in a starship, intending to return to their base in the Undercity. However, they were pursued by the Heroes of Cularin, who had traveled to Coruscant with Qel-Bertuk's fleet. While attempting to evade their pursuers, the cultists crashed their ship in the Undercity. They abandoned the Believer Blaise, who had been injured in the accident, and returned to the bunker with the box. A group of Believers gathered in the base, preparing to open the box. While the cultists were distracted by their prize, the Heroes of Cularin entered the bunker and attacked them. The agents overpowered the Believers, seized the Mandalorian iron box, and transported the fragment of Conkesta to the Jedi Temple.
Shortly after the Pulas' transportation was completed, Qel-Bertuk and the Wookiee Jedi Master Kirlocca were interviewed by a reporter about the Believers' emergence, discussing the threat the cult posed to the residents of the Cularin system.
Some time later, Len Markus, the founder of the Believers, seized an ancient Sith artifact known as the Darkstaff from the Cularin asteroid belt, causing the Cularin system to be transported ten years into the future to approximately 21 BBY, during the era of the Clone Wars. The artifact possessed Markus, and under its influence, he ascended through the Believers' ranks to become the cult's new leader. The Believers evolved into a formidable force, and during the Clone Wars, several Jedi stationed in the Cularin system fell to the dark side and joined the cult. The Believers established themselves as a power in the criminal underworld of the Cularin system, and around 21 BBY, they launched a clandestine campaign to eliminate their criminal rivals, selecting the Metatheran Cartel as their initial target. The Cartel was a trading organization led by members of the Caarite and Filordi species. To undermine the Cartel's influence, the Believers acquired a deadly virus fatal to Caarites. The cultists refined the virus and chose a hidden Metatheran Cartel base on the moon Tilnes as a testing ground for the infection, knowing that the Cartel would not publicize an outbreak within the facility due to the secrecy surrounding its existence. They released the virus into the facility via a bomb wired into the complex's circuitry. The infection wiped out all the Caarites inside the base, except for Ko Bas, the overseer, and two others, who mutated and transformed into raging killers.
A team of six Human Believers gathered in a bar in Tolea Biqua on Genarius and traveled to the Cartel base on Tilnes to assess the outbreak's results. However, while inside the facility, a burst of electromagnetic pulse from Tilnes' core struck the base, shutting down its power systems. When the power returned after the pulse, the base's emergency seal activated, trapping the Believer team inside. The mutated Ko Bas captured and killed four of the Believers, and the two survivors, Aris and Osia, sought refuge in the complex's security office.
The Believers improved and further produced the virus from a secret laboratory located within the manufacturing station S-Ipsus on Genarius. Once the virus was ready for deployment, the Believers sent a transmission to the laboratory, ordering the facility's inhabitants to abandon S-Ipsus and destroy any evidence of the cult's presence. However, both the crime lord Nirama and the Cartel intercepted the transmission. Convinced that the Believers posed a threat to the Cularin system, Nirama hired the Heroes of Cularin to destroy the virus production facility, while the Cartel independently dispatched its own strike team to do the same. Before the agents and the Cartel arrived at the base, the Believers shipped large quantities of the infection from the laboratory inside three transports, which headed to the Caarimoos system via circuitous routes, preparing to disperse the virus on Caarimon, the Caarite homeworld. Shortly afterward, the Heroes of Cularin and the Cartel team landed on S-Ipsus. The agents confronted the Believer Canduri on a thermal detonator production line, while the Cartel team launched an attack on the laboratory. The Believers inside the base were caught off guard, and the Cartel wiped out all of the laboratory's inhabitants.
The Believers hired the assassin Melo Centris to help them disperse the virus in Caarimon's upper atmosphere, hoping to kill over half of Caarimon's native Caarite population. Additionally, the cultists planned to cause a major environmental catastrophe on Caarimon by crashing escape pods packed with explosives into fault lines in the Desolation region of Caarimon, triggering a groundquake. The three Believer transports from Genarius arrived in the Carimoos system under the escort of the Z-95 Headhunter Ku'Amo, and two of the starships docked with Creautaa-V, a research station orbiting Caarimon. Centris and a group of Believers led by the former Jedi Crymsin Ost, the commander of the Caarimon operation, entered the station and released the virus, killing all the Caarites aboard the facility. Meanwhile, the third transport landed in the city Joventusek on Caarimon, and a team of four Human Believers disembarked from the vessel. The Believer team then hired some T3-OR speeder bikes and traveled to the city Efellis, where they contacted a local information broker and obtained data regarding the world's fault lines. Afterward, the team biked to the Desolation and planted a homing beacon to guide the explosive-filled escape pods to the fault lines. To prevent anyone from interfering in the cult's plans, the Believer team took up a position 30 kilometers north of Joventusek, under orders to kill any off-worlders attempting to travel toward the Desolation.
The Cularin Militia, a military force active in the Cularin system, received intelligence reports indicating that a number of Believers were converging on Caarimon. The Militia deduced that the cultists planned to release the anti-Caarite virus on the planet. To prevent the Believers from completing their plan, the Cularin Militia hired the Heroes of Cularin to thwart the cult's activities on Caarimon. The agents traveled to Caarimon and attempted to reach the Desolation. However, en route, the Believer guards stationed north of Joventusek ambushed the agents, initiating a speeder bike chase. The agents defeated the Believer team and disabled the Believers' homing beacon. The agents proceeded to fly to Creautaa-V, confronting Centris and Crymsin Ost's Believers aboard the station and preventing them from releasing the virus. During the skirmish, the agents recovered information from Centris' datapad implicating the Thaereian military, an armed force based in the Thaere system, in conspiring with the Believers to wipe out the Caarites. However, the agents were uncertain whether the data was genuine.
To commend the Heroes of Cularin for preventing the Believers from releasing the anti-Caarite virus on Caarimon, the Metatheran Cartel held a celebratory party on Dorumaa, the moon of Almas. During the event, a rumor circulated that someone was planning to attack the party, and some attendees falsely suspected that the Believers would launch a strike against the celebration.
At a later point, the Heroes of Cularin encountered the "shadow lurkers," disembodied spirits of the Oblee species residing in the Cularin asteroid belt. The Darkstaff drew energy from the shadow lurkers via three crystal shards located in the asteroid belt. The spirits requested that the freelance agents destroy the shards to sever the Oblees' connection to the staff. The Darkstaff sensed that someone other than the shadow lurkers had contacted the shards. At the artifact's behest, Len Markus sent a group of Believers to the asteroid belt, ordering them to either kill the individuals who had disturbed the shards or recover the three shards. The group of Believers, including the Trandoshans Gaar and Ulis, the Wookiee Rorvek, and several others, landed on the asteroid housing the shards and attacked the Heroes of Cularin. However, the agents defeated the Believers and freed the Oblee from the Darkstaff's grasp.
Around this time, a slicer posted a message on the Cularin holonet node, discussing the creation and role of the Sith battlelords, a class of warriors who had served Darth Rivan. However, the Cularin system's media subsequently declined to discuss the article, fearing that doing so would attract the Believers' attention to the posting.
The Believers began collaborating with the Wyrd, hoping to usurp the Tarasin witches' Force abilities to use the Wyrd's powers against the Jedi. The two organizations planned to launch a strike against the Almas Jedi and fracture the Cularin self-governance movement, a political campaign backed by the Cularin Militia that sought to force the Thaereian military to withdraw its troops from the Cularin system. To that end, the Believers and the Wyrd conspired to link the self-governance movement with the Confederacy of Independent Systems, a separatist government opposing the Galactic Republic. The Believers allied themselves with the Separatists, and the cultists and the Wyrd agreed to share documentation with the Confederacy on how to undermine the self-governance movement. Additionally, the cult established links with the Thaereian military. However, unbeknownst to the Believers, the cult's collusion with the Separatists, the Thaereians, and the Wyrd resulted from the machinations of the Sith Lord Darth Sidious. The Believers eventually occupied an abandoned Separatist base located in a deserted star system.
As the Clone Wars progressed, the protest group Truth For Cularin produced several HoloNet documentaries speculating on issues affecting the Cularin system. In one such documentary, Jarik Vuintor claimed that the Believers were an arm of the Jedi Order, where the Jedi transferred failed students deemed unsuitable for the Jedi life. Vuintor also speculated that the cult was funded by Lavin Wren, the Cularin system's senator, to allow Wren to use the cult to advance her political career.
Around 19 BBY, Len Markus and elements of the Believers provided the Wyrd with information obtained from studying Sith mutational practices. Using Markus' information, the Wyrd developed the Ritual of the Power of the Dark, attempting to turn the World Tree, an interconnected network of ch'hala trees growing on Cularin, to the dark side. However, the Wyrd's plans failed, and the Cularin Armed Forces (CAF) subsequently obtained evidence that the Believers had provided the Wyrd with the knowledge to perform the ritual. The CAF also learned that the Believers were operating from the abandoned Separatist facility and began planning an attack on the base to capture Markus.