Once a Imperial Sovereign Protector and aspiring Sith Lord, Carnor Jax, a male Human warlord from the fallen Galactic Empire, attempted to seize the then-empty throne. Following the deaths of Emperor Palpatine and Darth Vader, Jax became the second apprentice of Lumiya, the self-proclaimed Dark Lord of the Sith, and served her. Together, Jax and Lumiya eradicated the last remaining Prophets of the Dark Side residing on Bosthirda.
After Palpatine's resurrection in multiple clone bodies, Carnor Jax successfully orchestrated the demise of Palpatine's final clone, thereby assassinating the Emperor and paving his own path to the throne. Jax was also responsible for decimating the Royal Guard, nearly wiping them out in a surprise assault on the planet Yinchorr. Kir Kanos, the sole survivor, was forced into hiding, compelling Jax to dedicate his resources to capturing him. This pursuit led Jax to capture Mirith Sinn, a Rebel leader, and subject her to torture.
However, fate intervened, and Kanos's actions facilitated Sinn's escape, culminating in a final confrontation between Jax and Kanos on Yinchorr. Despite the battle being closely contested, Kanos's unexpected skill tilted the balance, resulting in Jax's death. Following Carnor Jax's demise, Lumiya remained without a known apprentice for nearly three decades.
Carnor Jax was the offspring of a Thyrsian Sun Guard warrior, who was executed by Darth Sidious, a Sith Lord, after failing to retrieve the Holocron of King Adas.

In his youth, Jax entered the Galactic Empire's ranks as a stormtrooper, even serving under Agent Blackhole as one of his Blackhole stormtroopers. Jax distinguished himself within his unit as an exceptional soldier, quickly earning recognition and transfer to Royal Guard training. Along with forty-three other candidates, Jax was sent to Yinchorr, from which the original inhabitants had been removed, creating an ideal training ground for Emperor Palpatine, secretly known as Darth Sidious, and his elite warriors.
Under harsh conditions, Jax underwent rigorous training, mastering the lethal Echani fighting style. This was complemented by comprehensive instruction in the use of the force pike and vibroblade, particularly the double vibroblade. Supervised by Master Ved Kennede, Jax and the other recruits tested their skills in an arena called the Squall. It was here that Jax first encountered Kir Kanos, with whom he frequently sparred. Jax consistently triumphed in these encounters, relishing his dominance over Kanos. Both were initially trained by Myn Kyneugh.
While Jax and Kanos excelled in their class, Burr Danid stood out for his flawless technique and unparalleled skill. Danid was considered the best recruit when Emperor Palpatine made a surprise visit. Jax and Kanos observed as Darth Vader, Palpatine's foremost disciple, requested that Danid join him in the Squall. Under the Emperor's watchful eye, Vader instructed Danid to attack him without holding back. Despite Danid's perfect form, Jax recognized that Vader was merely toying with him. Vader brutally killed the young man before the assembled recruits. While Kanos was horrified, Jax remained stoic, fully grasping the lesson being imparted, and subsequently dedicated himself to becoming the best in his class.
As the initial group of recruits dwindled, the remaining men were paired to foster reliance on their "brothers." The trials and training intensified, forcing the pairs to depend on each other to complete their tasks. Jax was paired with Alum Frost, with whom he lived and trained for a year. Jax held Frost in low regard, attributing their success solely to his own efforts. Despite their less-than-ideal teamwork, Jax and Frost were among the final two pairs to survive the rigorous training.

After a year, Jax and Frost, along with Kir Kanos and Lemmet Tauk, were informed by Master Kennede that they had completed their training, save for a final test before the Emperor. The four men were to be brought before the Emperor in pairs. Jax and Frost were the first, handed vibroblades and ordered to fight to the death to prove their worth. Jax easily killed Frost, completing his training.
Frost's body was removed as Tauk and Kanos entered. Jax watched as they underwent the same trial. He observed Kanos kill Tauk, and was then humbled by Darth Vader's skill. In a private ceremony, Palpatine, Vader, Kanos, and Jax elevated the two trainees to the rank of Royal Guard.
Little is known about Jax's service in the Royal Guard, but he likely served with distinction as one of the Emperor's bodyguards. However, Jax's loyalty was not to Palpatine, but to his own ambition and potential for advancement.
Jax was not on the second Death Star during the Battle of Endor, thus avoiding death. Stationed on Coruscant with the remaining Royal Guard, Jax served under acting Emperor Sate Pestage and later Director of Imperial Intelligence Ysanne Isard. When Lumiya, the Dark Lady, requested a Royal Guard detachment from Isard, Jax's unit was sent. Recognizing Jax's Force potential, Lumiya began training him as her Sith apprentice. They later located and executed the last of the Prophets of the Dark Side on Bosthirda. Jax specialized in telekinesis and precognition during his Force training, possibly receiving instruction from other Dark Side Adepts.
Under Lumiya's guidance, Jax met influential figures in Imperial politics, including Sarcev Quest, an ambitious Dark Jedi and member of the Imperial Ruling Council. Quest saw Jax as a potential figurehead and military commander, and together they sought to seize control of the Empire. Quest used his influence to provide Jax with a task force led by the Star Destroyers Emperor's Revenge and Steadfast, and a military contingent under General Redd Wessel.
Jax, a former soldier, preferred Army officers over Navy personnel, unlike most warlords. He also appointed Lieutenant Geff Blim as his 'hand,' similar to Mara Jade's role for Palpatine. He encountered Nom Anor, later informing Lumiya about the agent. However, Jax's death severed the connection, preventing Lumiya from pursuing a proposed Sith alliance with this extragalactic race.

When Palpatine reclaimed the Empire in 10 ABY, Jax rejoined the Royal Guard, but remained loyal to his allies. Jax knew he would soon confront the Emperor. Jax and Quest planned to depose Palpatine and seize the throne. Quest secured Jax's appointment as an Imperial Sovereign Protector, using this position to orchestrate a widespread conspiracy. Under Jax's orders, General Wessel gained support from senior military commanders, influential civilian loyalists, and alien leaders such as the Whiphid spearmaster.
Meetings to rally support for Jax's plan were conducted with extreme secrecy. Anyone disagreeing with Jax or suspected of revealing the plan to Palpatine was immediately executed, often by Blim. Several times, exposure seemed imminent, but Blim's quick actions prevented the plan's discovery.
Using funds from Quest and Wessel, Jax bribed the Emperor's physician to sabotage Palpatine's remaining clones. He also used funds to erase himself from the Royal Guard's database. The sabotage caused Palpatine's final clone body to rapidly age and deform, forcing him to seek a new body. The Emperor was ultimately destroyed on Onderon, and while R2-D2's efforts led to the demolition of the Deep Core throneworld of Byss, Jax's plan exceeded his expectations. Unbeknownst to Jax, he had avenged his father's death.

Unfortunately, the captured physician revealed his betrayal and Jax's bribery. Eavesdropping, a Royal Guard overheard the confession and escaped to Yinchorr, where the remaining Guards mourned.
To conceal this, Jax sent stormtroopers to eliminate the remaining Royal Guards. Despite inflicting heavy casualties, the Guards were overwhelmed. Kir Kanos, Jax's rival, escaped, infuriating Jax. Aware of Kanos's potential to disrupt his rule, Jax placed a large bounty on Kanos and deployed forces to capture him.
Meanwhile, Jax's backers seized power, with Quest leading a new Imperial Ruling Council filled with Jax's supporters. The Council allied with Jax as Dark Lord of the Sith and de facto Emperor. Wearing a modified Royal Guard uniform reserved for the Yinchorri Academy's master trainer, Jax planned to crush the New Republic and continue the Empire's resurgence. Though he sometimes commanded from the Star Destroyer Emperor's Revenge, Jax ruled his Crimson Empire from a villa on Ord Cantrell, an Outer Rim world. He oversaw the Imperial Ruling Council, which, under his leadership, included unprecedented non-Human members: Whiphids, Defel, Givin, and Devaronian. Jax's empire extended from the Outer Rim to the Mid Rim, encompassing worlds like Qiilura, Celanon, the Kol Huro system, and the D'Astan sector.
However, Jax prioritized capturing and executing Kanos. He tracked Kanos to Zaddja, only to find a trap that killed many stormtroopers. To replenish his forces, Jax recruited the remaining Blackhole stormtroopers and retrained them to defeat Kanos.

Aboard Emperor's Revenge, Jax learned of a man who single-handedly killed four Imperial officers and a squad of stormtroopers in a tapcafe. Certain he was about to capture Kanos, Jax set course for Phaeda, the report's origin. However, Kanos escaped due to the local militia's incompetence. Jax discovered that Kanos had been staying with Rebels led by Mirith Sinn. Jax's forces captured Sinn and subjected her to torture. Only Jax's Force-assisted torture broke her, revealing Kanos's flight to Yinchorr. Leaving Steadfast to bombard the Rebels, Jax boarded Emperor's Revenge and headed for Yinchorr.

Arriving at Yinchorr, General Wessel spotted Kanos's ship and prepared to board it. Sensing a trap, Jax, with his Blackhole stormtroopers and Blim, took a shuttle, leaving the Star Destroyer. As Jax's shuttle departed, Kanos's booby-trapped ship exploded, destroying Emperor's Revenge and killing Wessel.
Landing on Yinchorr, Jax ordered Blim to hide and kill Kanos if he gained the upper hand. Jax and his squad approached the Yinchorri facility. Jax sent his squad to flush out Kanos. Sensing their deaths, Jax entered and faced Kanos alone. Following Kanos's path, Jax found him in the Squall, where he had always prevailed.

Using the Force, Jax was a formidable opponent, but Kanos's fury proved equal. Signaling Blim to shoot Kanos, Jax found Blim dead, killed by Rebels Sish Sadeet and Mirith Sinn, the woman he had tortured. The Rebels hoped to capture Jax and end the war. With Blim dead, Jax tried to exploit Kanos's attachment to Sinn. Using the Force to pull Sadeet's blaster, Jax prepared to shoot Sinn. Kanos reacted instantly, deflecting the blaster and stabbing Jax. As Jax died, he claimed Kanos's friend wanted him alive. Kanos coldly replied they were not his friends, removed Jax's helmet, and declared him unfit to wear it. Jax's body lay undisturbed as Kanos left the planet.

Carnor Jax was a gifted soldier with considerable ambition. Even during his Royal Guard training, Jax strived to be the best. Despite his high self-opinion, he recognized the importance of powerful allies, as evidenced by his relationships with Sarcev Quest, Lumiya, and members of the Imperial Ruling Council.
This ambition and awareness of allies made Jax adept at identifying potential threats, recognizing Kir Kanos's danger to the Empire. Beyond his calculating nature, Jax had a volatile temper with subordinates and tolerated no failure. His training in the dark side likely contributed to this, as he was less prone to anger during his time at the Imperial Royal Guard Academy.
Carnor Jax excelled as a stormtrooper, earning the chance to train as a Royal Guard. On Yinchorr, he was considered one of the best trainees, defeating opponents in the Squall with martial arts and vibroblade skills. His skill and determination helped him become a Royal Guard.

Trained by Lumiya, Jax was skilled in the Force, often practicing aboard the Emperor's Revenge by levitating and crushing spheres with telekinesis. His telekinesis allowed him to manipulate a rock during his final duel with Kanos and pull Sadeet's blaster. Jax also possessed a developed Force Sense, detecting Mirith Sinn's lies during interrogation. Despite considering himself nearly as powerful as Palpatine and Vader, his training was insufficient to defeat Kir Kanos on Yinchorr.
Carnor Jax was voiced by Robert Downing Davis in the audio drama version of Crimson Empire.
Randy Stradley stated that Crimson Empire was written with the idea that all Royal Guards were clones, with Jax's unmasked face suggesting he and Kanos were from the same prime clone. However, Jax's father's existence seems to contradict this, unless the original Jax was a prime clone like Jango Fett.
In 2021, a "Carnor Jax" action figure was released for Lucasfilm's 50th Anniversary. This was an error, as the figure was based on Kir Kanos.