There was no indication Agen Kolar's Jedi career was non-traditional—force-sensitive, he was likely recruited by the Jedi Order at a young age, tutored in the Jedi Temple, and apprenticed to a Jedi Master before passing his trials to become a Jedi Knight.
Kolar was frequently assigned to missions across the Mid Rim, traveling to the edges of Republic authority and beyond. Hutt Space was one area in which he was known to operate, gaining an acquaintance, though hardly friendship, with the Besadi kajidic overlord Aruk Besadi Aora. Kolar also partnered with other Jedi on Rim missions, such as Quinlan Vos. Kolar gained prominence and respect among the Jedi for his skills and exploits, though his finesse in conducting diplomacy was notoriously lacking; he instead preferred to act, aggressively if necessary.
By 22 BBY, Kolar held the rank of Jedi Master, presumably having trained a Padawan to Knighthood previously, and was one of the Order's leading members, known as one of its best swordsmen. At that time, his Padawan was a male human, Tan Yuster.
When word reached the Jedi Council that Jedi Knight Obi-Wan Kenobi had been captured on Geonosis while investigating an assassination plot and after having stumbled upon an ominous meeting of the Confederacy of Independant Systems, Kolar and Yuster were among the Jedi present in the Temple. Both were summoned to follow Mace Windu as part of the strike force sent to rescue Kenobi.
The pair were among the Jedi who infiltrated the galleries of the Petranaki arena, where Kenobi was to be executed. On Windu's cue, Kolar and his fellow Jedi revealed themselves in a show of force, but Confederacy leader and former Jedi Count Dooku deployed a force of battle droids against the Jedi. Kolar and Yuster battled fiercely, cutting their way onto the arena floor, but numerous Jedi began falling to the massed fire of the battle droids. Kolar and Yuster joined a circle of Jedi survivors on the arena floor, but Yuster fell in combat among them. When the situation looked most grim, with the few Jedi surrounded by an army of battle droids, Grand Master Yoda arrived at the head of the newly-commissioned grand army of the Republic. Kolar was saved and joined the battle against the Separatist armies on-planet, becoming one of the few survivors.
Kolar was saddened by the loss of his Padawan, but stayed true to the Jedi principle of non-attachment, accepting Yuster's death and moving on. With the Clone Wars begun, Kolar was made a Jedi General in the Grand Army of the Republic. Ever a follower of the Council's will and a strong believer in the Jedi's duty to the Republic, he disdained those Jedi who opposed the decision to take an active role in the war. When Mace Windu discovered that the esteemed lightsaber trainer Sora Bulq had fallen to the dark side and joined Dooku, he warned Kolar of the betrayal and Bulq's history with Vaapad.
Five months into the war, Kolar was assigned to retake Brentaal IV, a Core World located at a key hyperspace transit point, from an insurrection led by local clan leader Shogar Tok. Kolar, under the command of Jedi Council members Plo Koon and Shaak Ti, landed his troops on the planet, but the Republic's intelligence was faulty; Tok's ion cannons were operational and shielded, tearing the landing force to pieces. A quarter of the overall forces, along with Jedi General Shon Kan Ray, were lost almost immediately. Kolar was hard-pressed, though he retained many of his soldiers.
Ti found sanctuary in a prison, where she recruited several prisoners to aid her in infiltrating Tok's fortress via a sewer connection between the two facilities. In order to help her accomplish that, she ordered Kolar to lead an assault on the north face of Tok's citadel. Once she was inside, Koon, in orbit, would retreat and return in four hours, by which time she hoped to have sabotaged the defenses or captured Tok. Kolar, on the surface, was given the option to retreat or surrender.
When that time came, Kolar surrendered, along with his troops. He was brought before Tok and the holographic presence of Dooku, who interrogated him as to Ti's whereabouts. Kolar briefly resisted, earning him a beating at Tok's hands, before he testified that he had felt her die in battle through the Force. Kolar was imprisoned while Tok's forces searched for her body. There he remained until Ti succeeded; he and his troops were freed by two of her recruited prisoners: Jedi Master Quinlan Vos, Kolar's old ally, and Sagoro Autem. Ti was badly wounded after a betrayal by one prisoner, though, and Kolar took command on the ground in the aftermath while Ti recuperated in a bacta tank.
One month later, Jedi Masters Windu, Yoda, Ki-Adi-Mundi, and Tholme decided to use Kolar in a ploy. Vos, already under suspicion of deliberately providing the faulty intelligence for Brentaal, would be inserted into Dooku's camp as a double agent. However, they needed convincing evidence of Vos's break with the Order. To that end they provided him with high-value military codes which he was to attempt to sell to the Separatists, and the Council sent Kolar after Vos without the Zabrak Master knowing of Vos's true role.Only that small faction knew the entire scope of what was planned; Kolar was chosen for his unquestioning obedience to the Council and the likelihood Kolar would do his utmost to avoid delivering a killing strike.
Kolar traveled to Nar Shadda with three clone troopers in plain clothes. As Nar Shaddaa was in Hutt Space, the Republic had no legal grounds to arrest Vos there, but Kolar hoped to move swiftly and covertly and leave without the Hutts even being aware of a Republic presence.
Kolar's troopers raided Vos's attempted sale while he waited outside. Vos fought back, escaping the building, but Kolar force pushedhim into a wall and drew his lightsaber, capturing him. Vos was manacled and placed in a speeder next to Kolar. In his hurry to leave, Kolar allowed Vos's agent, Khalen Hentz, to escape. Vos protested his innocence, maintaining that he was attempting to feed the Separatists false information. Kolar, however, demonstrated that the codes were accurate. During their ride, Kolar and Vos briefly discussed whether the Separatists might have a point, but Kolar insisted that, as the Council had chosen to oppose them, the Jedi had no business supporting the Confederacy.
Their conversation was interrupted by the arrival of Hentz in her own speeder. Vos leaped aboard it, and Kolar and his troopers pursued. Vos jumped from Hentz's speeder in flight, hoping to avoid Kolar's notice, but Kolar was not deceived and leaped to follow, ordering his soldiers to continue their pursuit of Hentz. Kolar cornered Vos and engaged him in a duel, quickly disarming him. Kolar pleaded for Vos to return peacefully with him to Coruscant, where he could find his way back to the light. Vos attacked, and Kolar struck back, delivering a warning slice across Vos's shoulder armor to make the point that Vos was outclassed and should submit. Instead, Vos sliced open a cage of amphibians and ran while Kolar dealt with a tide of the creatures.
Kolar pursued Vos through a cantina and onto a dead-end walkway just outside it. However, the cantina's patrons knew Vos from his previous undercover work and moved to defend him. When the mob confronted him, Kolar disarmed them with a simple Force Pull. The group was enraged; Kolar deactivated his lightsaber and ordered them to move on or accept the resultant damage. When they charged, Kolar began to engage them in unarmed combat, mowing though their numbers. He was interrupted by the arrival of Aruk the Hutt, who owned the cantina. The Besadii kajidic overlord demanded to know why Kolar was beating his customers; Kolar replied that he was on Republic business. Aruk pressed Kolar to leave, threatening a major diplomatic incident if he persisted. Knowing that pushing the Hutts away from the Republic and possibly into the arms of the Separatists was not worth Vos's capture, Kolar reluctantly allowed himself to be led back to his ship by Besadii guards. One bright spot did exist for the mission, however: besides preventing the actual sale of the codes, the clone troopers had captured Hentz.
Kolar was debriefed by the Council and sent back to his newly resupplied forces in the field; he transferred Hentz to Coruscant, but was told that it would be fruitless to attempt to pursue Vos further. Not all of Kolar's time would be spent on the front lines, however, as he was appointed to the Jedi High Council by sixteen months after Geonosis, becoming a part of the decision-making process which he had previously obeyed unquestioningly. Frequently on Coruscant, Kolar received reports of the war's progress along with the other Masters, deciding as much as acting.
After seventeen months of war, a new threat emerged: the Crimson Nova chapter of the Bounty Hunters Guild had begun accepting bounties on Jedi. Windu decided that, with a few Jedi, he would be able to make a potent show of force and send the message that such action would not be tolerated. Windu recruited Kolar, along with Council members Saesee Tiin and Kit Fisto, to travel to The Rig, the spaceborne headquarters of the Crimson Nova chapter, and dismantle their operations.
Windu announced his visit and apparently arrived alone, keeping the bounty hunters' focus firmly on him as he demanded Mika, head of the chapter, put an end to the bounties and surrender into his custody. Meanwhile, the other three Jedi arrived covertly. Kolar, under the alias " Argent Kole ", posed as a bounty hunter, with Fisto as his bounty. When The Rig's records naturally failed to find "Kole" among their registered bounty hunters, Kolar railed against poor record-keeping on the Guild's part and demanded his bounty be processed immediately. Looie, the being operating the redeption center desk, was sufficiently intimidated to process Fisto
Fisto escaped from his false cuffs and freed the other bounties, inciting a prison riot. Kolar and the other hunters were denied their bounties until the prisoners were rounded up again, building resentment, which Kolar demagogued into a revolt on the bounty hunters' part as well, leaving The Rig in chaos. With Tiin causing an explosion that destroyed The Rig's supplies and its hangar, Mika vowed to kill Windu. Seeing no negotiation was forthcoming, Windu reunited with the other Jedi for an assault on The Rig's leadership.
In he Nest, Mika refused one last chance to surrender. Windu and Fisto engaged Mika and her enforcers while Kolar and Tiin attempted to take the control room. The two cut their way in, where Kolar secured the station's blast doors, cutting off reinforcements, and disabled the escape pods. They also intended to search the files to find out who offered the bounties on Jedi, and may have done so.
With that accomplished, the pair set out to reinforce Windu and Fisto, but arrived just after Mika was stunned by her lieutenant Stroth, who could see that Mika's vendetta against the Jedi was against the Crimson Nova chapter's interest. Stroth gave up Kh'aris Fenn, who had posted the bounties, to the Jedi. Kolar and the other three Jedi followed Stroth's directions and found Fenn dead in his Ryloth fortress. Quinlan Vos had left a hologram of Fenn's death at his hands as a warning from Dooku; after viewing it, the four Jedi came to the conclusion that Vos's fall was a ruse no longer. They believed that among Dooku's Dark Acolytes, Vos's deception had become reality. Kolar blamed himself for not having brought Vos in successfully on Nar Shaddaa.
Kolar continued his role on the Jedi Council, spending time on Coruscant, and aiding that body's deliberations. In 20 BBY, when the Padawan Flynn Kybo came before the Council to request that they approve an assassination mission against General Grievous, the Separatist supreme commander and a notorious Jedi-killer, Kolar was among those who opposed Kybo's plan, citing the amount of resources that would be tied up in use against one individual, though it was only later that Kybo clarified that his plan was not assault, but assassination. Kybo eventually undertook the mission without sanction, proving unsuccessful. Kolar also participated in the discussion regarding the Knighting of Anakin Skywalker, suggesting the young Jedi hero had yet to face the Trial of the Spirit. When it was decided to promote Skywalker, Kolar and the rest of the Council participated in his Knighting ceremony.
Kolar was able to indulge his taste for action as well, taking the field when called upon. On one such occasion, Kolar, Aayla Secura, and Voolvif Monn undertook a mission to an icy planet, where they were engaged by crab droids and trapped by their bubble wort projectors. Kolar might have become a Separatist captive if not for the intervention of Skywalker, who destroyed the droids, freeing the three Jedi. By this time, Kolar had either constructed a new lightsaber, or simply changed the crystal of his lightsaber from green to red. That change would be short-lived, as Kolar wielded a blue-bladed lightsaber only a few months later.
Another field mission was the Battle of Boz Pity. After tips provided by Obi-Wan Kenobi led to the discovery of a significant Separatist presence on Boz Pity some thirty months into the war, the Venator-class Star Destroyer Intervention dispatched along with an unusually strong complement of Jedi—including eight Jedi Council members, among them Kolar. Skywalker was also in the complement, and piloted the Intervention past the Separatist blockade of the world, but was unable to avoid a crash landing. On the planet, Kolar and the others made their way to the main Separatist base, where they found Dooku, Grievous, and Asajj Ventress—all high-value targets. Kolar engaged the many squads of battle droids surrounding the fortress, but was never given the opportunity to engage in a lightsaber duel; Dooku dueled Windu and escaped, Grievous killed Soon Bayts and Adi Gallia before being badly damaged by Windu and forced to retreat, and Ventress was brought down by Dooku's forces after the Count decided to eliminate an unreliable asset.
A full three years after the war began, Grievous struck at Coruscant. Kolar took to space, battling against the Confederate Navy in his starfighter. While he was so occupied, Grievous was able to sneak planetside and capture Supreme Chancellor Palpatine from his offices. Kolar, Tiin, and Pablo-Jill were recalled from the battle to attempt to intercept Grievous's escape shuttle. They repeatedly engaged it, but were repelled by debris fields created by Grievous. Grievous could not outmaneuver them as they closed and chewed away at his shields, but he did destroy civilian ships caught in the crossfire any time Kolar or the others got too close, forcing them to fall back. Despite Kolar's efforts, Grievous was able to make it to his flagship, the Invisible Hand, and Kolar presumably continued to fight until Skywalker and Kenobi arrived and were able to rescue the Chancellor, kill Dooku, and force Grievous to retreat.
Kolar remained on Coruscant, serving on the Jedi Council. He supported the Council's request for Skywalker to use his closeness to the Chancellor to spy upon his office, as the Jedi had grown increasingly suspicious that a Sith Lord, Darth Sidious, was manipulating Palpatine and had in fact manufactured the entire war. Kolar had great faith in Skywalker's abilities, and suggested it was vital that Kenobi, whom Skywalker trusted, be the one to ask him. He also suggested that the Council emphasize that it was stepping up the search for Grievous, which Skywalker would report to Palpatine, hopefully forcing Sidious into action to protect his pawn. He was also the one to suggest that, of Yoda or Windu, Yoda be the one to take the field in a ploy to cause Sidious to feel overconfident and draw him into action. Yoda would lead the defense of Kashyyyk, Kenobi would put an end to General Grievous, and Kolar would remain on Coruscant, along with Windu and several other combat-hardened Masters, ready to counter Sidious.
When the Council was informed that Kenobi had killed Grievous in combat, they moved to confront Palpatine and force him to lay down his emergency powers, which he had been accumulating in excess and the Council feared could be used by Sidious for unsavory ends, now that the war was largely ended. Windu reassembled the same team he had used at The Rig, preparing to lead Kolar, Tiin, and Fisto into the Chancellor's office. As they were preparing to depart, however, Skywalker arrived with shocking news: Palpatine had revealed himself to Skywalker as being Darth Sidious; the Republic was ruled by a Sith Lord. Windu ordered Skywalker to remain in the Temple and set off with the three Masters. Fisto was apprehensive, and Kolar wanted to know why Skywalker was not with them. Windu and Tiin were able to reassure them, and the group departed for Palpatine's office at sunset in a LAAT/i gunship, ready to arrest him.
Kolar brought up the rear as the four Jedi Council members strode into Palpatine's office. Each lit their lightsabers as Windu declared Palpatine under arrest. A brief discussion led to Palpatine drawing his lightsaber and leaping across his desk, landing and stabbing Kolar, who was unable to bring his blade into position swiftly enough, through the torso, ending his life. Kolar crumbled to the floor, muttering his last words: "It doesn't … hurt …"
Tiin was killed in very short order, and Fisto soon followed. The duel concluded when Skywalker arrived and intervened—on the side of the Sith Lord who had manipulated the entire war into being. Kolar's trust in Skywalker had been misplaced. Palpatine killed Windu, made Skywalker his Sith Apprentice, and transformed the Republic into the Galactic Empire, declaring the Jedi enemies of the state on the basis of the attempted arrest Kolar had helped perform. Agen Kolar effectively became the first victim of the Great Jedi Purge.