The Human male named Jace Dallin, hailing from the planet of Rendili, dedicated his life to military service and held a profound affection for the Galactic Republic. He functioned as an aide to the Militarist Senator Ranulph Tarkin and also served as the second-in-command within Tarkin's military unit, known as the Republic Outland Regions Security Force. In the year 44 BBY, Dallin became entangled in the Stark Hyperspace War when Tarkin made the decision to guide his fleet towards a meeting with the Stark Commercial Combine, which was essentially a group of pirates. The fleet was subjected to an ambush orchestrated by Iaco Stark's forces in a bid for power, and Dallin narrowly survived, reaching the surface of the planet Troiken. There, he allied himself with the Jedi delegation attending Stark's summit and defended their position for several days from the safety of an abandoned spice mine. Dallin commanded Tarkin's army in opposition to Stark's forces and cultivated a deep respect for the Jedi leader, Master Plo Koon. During the fighting, Dallin sustained a facial injury. Lacking access to bacta, the wound resulted in a prominent facial scar.
After surviving the war, Dallin became a member of the Republic's Judicial Forces. Following his service there, he went back to his homeworld and enlisted in the Rendili Home Defense Fleet, where he eventually rose to the position of fleet commander. In the final year of the Clone Wars, Rendili fell under the control of the Confederacy of Independent Systems, forcing Dallin to choose between adhering to the directives of his planet's government, now a Separatist puppet, or defecting to the Republic he held dear and against which he was unwilling to fight. A delegation headed by Koon arrived to engage in negotiations with him—and, if he refused to surrender, to eliminate Rendili's formidable fleet to prevent it from falling into enemy hands. Upon Dallin's expression of disapproval towards the Independent Provisional Government of Rendili, he and Koon were taken as hostages in a mutiny led by Lieutenant Mellor Yago. A Jedi squad then stormed Dallin's flagship, liberating Dallin, who regained command of the fleet and killed Yago in a gun battle on the bridge. Dallin then joined the Republic, but his service was short-lived; soon after the Declaration of a New Order, Darth Vader executed Dallin, who remained loyal to the Jedi, for questioning the new Galactic Emperor's assertion that the Jedi were traitors.

Originating from the world of Rendili, the Human male Jace Dallin eventually found himself working as an aide for Senator Ranulph Tarkin representing Eriadu. Tarkin, a passionate leader within the Galactic Senate's militarist faction, was dedicated to the re-establishment of the Republic Army and Navy. To achieve this, Tarkin established the Republic Outland Regions Security Force, a military "prototype" modeled after the Galactic Republic's existing Judicial Forces. Dallin, as his trusted confidant, served as the second-in-command of the self-proclaimed "General" Tarkin's paramilitary forces. Tarkin exclusively recruited Humans into his militia, and Dallin came to accept the General's humanocentric views.
In the year 44 BBY, the Trade Federation secretly collaborated with Thyferra's bacta-producing Xucphra Corporation to engineer an artificial shortage of bacta, thereby escalating the prices of this vital medicinal fluid and generating substantial profits for both entities. However, Iaco Stark, a smuggler, and his Stark Commercial Combine, a group of Outer Rim pirates, targeted the bacta-carrying freighters belonging to the Trade Federation. Stark then proceeded to sell this bacta at reduced prices, thus gaining a reputation as a hero throughout the Rim, despite his involvement in criminal activities. In an effort to resolve the conflict, the Senate convened a summit involving the Trade Federation, Stark, and the Republic to address the bacta shortage.
However, Tarkin firmly believed that the most effective solution to the crisis was to crush Stark's pirate organization through military force. With Dallin by his side, he entered into an agreement with Representative Nute Gunray of the Trade Federation; Gunray provided the location for the secret meeting, and Tarkin committed to arriving with the Outland Regions Security Force fleet to eliminate Stark. Tarkin's intention was to secure a resounding military victory, thereby demonstrating the value of a standing Republic army and navy and propelling himself into the position of Supreme Chancellorship upon his triumphant return.

Dallin and Tarkin prepared their fleet for action. Aboard the flagship called the Invincible, Dallin waited for Gunray's signal confirming that the conference on Troiken was underway. Upon receiving it, the armada jumped into hyperspace. Unbeknownst to Dallin and Tarkin, Stark had foreseen the betrayal and used it to legitimize his power grab. A navcomputer virus was secretly transmitted along with Gunray's signal, while Stark launched an attack on the delegates at the summit. The navigation computers of Tarkin's fleet were scrambled, causing the majority of the fleet to miss their intended destination. Dallin and the Invincible were among the one-third of the fleet that managed to reach Troiken, where they found themselves significantly outnumbered by Stark's own fleet. The Invincible sustained heavy damage from enemy ships as the fleet suffered decimation; Dallin looked to Tarkin for instructions, but the Eriadu commander was paralyzed by uncertainty in the face of this unexpected disruption of his plans. Senator Finis Valorum, the Republic's representative at the conference, had escaped with Gunray and their Jedi escort, and he contacted Tarkin with instructions to land at Mount Avos and seek refuge in an abandoned spice mine located within the mountain. Tarkin initially refused to take orders, but the Invincible was on the verge of total destruction, and after a particularly devastating hit, he relented. Dallin issued the orders to evacuate the troops and defend their escape pods; Tarkin repeated those orders moments later. The two then escaped in a life pod shortly before the Invincible was destroyed.
Dallin landed on the Lycinder Plain in front of Avos, where the surviving army troopers fled, entered the mine and began fortifying it while under fire from Stark's forces. They were soon joined by Valorum, Gunray, and Jedi Masters Plo Koon, Adi Gallia, and Qui-Gon Jinn, as well as Jinn's Padawan learner Obi-Wan Kenobi. Tyvokka, another Jedi Master, had died as a result of Stark's betrayal. After Valorum criticized Tarkin for facilitating Stark's trap with his secret fleet, Dallin took an active role in the mine's fortifications, inventorying the group's supplies and organizing the troops.
Koon employed his telepathic abilities to delve into Stark's mind, discovering Stark and his allies' plan to launch a surprise assault on the mountain. Dallin and the Jedi prepared, and the battle resulted in numerous soldiers being wounded, but it concluded as a Republic victory as Dallin's troops leveraged the high ground to repel Stark's advances. Furthermore, Koon's telepathy enabled him to anticipate any sorties and rally the Jedi against them. Following the battle, Koon and the other Jedi tended to the wounded—providing healing, comfort, and reassurance. Witnessing the Kel Dor Jedi serve without ego and demonstrate genuine concern for the troops shattered Dallin's humanocentrism. Additionally, Dallin became disillusioned with Tarkin due to the Senator's failure under fire, his displays of egocentrism, his failure to treat his soldiers as more than tools for his own ends, and the defeatist attitude he was displaying at Avos. Consequently, Dallin's loyalty began to shift from Tarkin to the Jedi: Tarkin was largely ignored as Dallin began taking his orders from Koon, for whom he developed an immense personal respect.
Following the battle, the Jedi devised a strategy to secretly transport Valorum and Gunray back to the Republic's capital world, Coruscant, where Valorum would appeal for reinforcements. With the communications of the Troiken group being jammed, they were presumed dead. Dallin pleaded with Koon to remain, recognizing that the troops looked up to him and relied on the Jedi Master for their morale. Koon agreed to stay while the other Jedi accompanied the diplomats, and Dallin led a diversionary battle while the other Jedi escaped from the caves. After aiding the others in acquiring a ship, Jinn and Kenobi returned to Avos, accompanied by Jedi Knight Tholme and his apprentice Quinlan Vos, who had stowed away on a freighter that arrived on Troiken from Thyferra after conducting an investigation of the bacta crisis. Meanwhile, one of Dallin's patrols came across the Xexto Billibango, a native who wished to aid the Republic. He warned them of the threat of challat eaters in the mines—huge swarms of flesh-eating insects. Just in time, the Jedi were able to bring down a section of the caves, trapping the newly awakened challat eaters.

Thanks to another warning from Billibango, the Republic was alerted to an imminent surprise attack by Stark's forces. Enemy troops surged into the caverns of Mount Avos, but Dallin's men rallied against them. During the battle, Dallin was wounded in an explosion; shielding from Billibango spared him from death. Dallin did, however, receive a large gash to the left side of his face. It was stitched up, but as the troops had no bacta, it healed into a large, distinguishing scar. After he awoke in the mine, Dallin spent the rest of the war with half of his face swaddled in bandages.
Koon was able to make telepathic contact with the Jedi Council through his niece, Sha Koon. The Republic refused to send aid, but the Jedi Council worked out a plan. Jedi reinforcements arrived over Troiken soon after, leading a task force of Trade Federation ships co-opted by a promise not to reveal the Federation's role in fabricating the bacta crisis. Stark was telepathically offered amnesty by Koon in return for betraying his forces, which he did. Koon planned to harmlessly trap Stark's army by retreating though the caverns, then sealing the entrances explosively. Dallin commanded the evacuation, but on reaching the exit—the last opening to be sealed—he found that Tarkin had disappeared with the charge that was to have been used to seal the exit. Tarkin, furious that Koon had usurped his command, was determined to go out a hero. He used explosives to clear the cave-in that had trapped the challat eaters, unleashing them on Stark's troops, who were devoured alive. Koon was the last to emerge from the cave, and he sealed the exit behind him with a Force-triggered rockslide. Stark's forces were defeated, and Dallin joined his troops in celebrating the end of the Stark Hyperspace War.

Following the conclusion of the war, Dallin enlisted in the Judicial Forces of the Republic. By 30 BBY, he was serving as a crew member on the Republic cruiser known as the Intrepid. In that year, the Intrepid was tasked with transporting a Jedi contingent, including Masters Mace Windu, Gallia, and Koon, to Kiffex, where they successfully rescued the Jedi Padawan Aayla Secura. Overjoyed to have Koon aboard, Dallin sought out the Jedi Master during the return journey to Coruscant. Koon was accompanied by Windu, Gallia, Tholme, and Secura. Secura gazed at Dallin's scars, which were unusual in a galaxy with access to bacta, and he described them as "battle flags" from the war. Secura had experienced memory loss during a failed mission, so the group recounted the events of the war to her. At the conclusion of the reunion, Dallin expressed his profound gratitude to Koon for the Jedi Master's service in the war, feeling that he owed his life to him.
Dallin eventually retired from his service to the Republic, returning to his homeworld of Rendili. There, he joined and later became the commander of the Rendili Home Defense Fleet. Holding the rank of captain, he commanded the fleet of Dreadnaught-class heavy cruisers from his flagship, the Mersel Kebir.
In 22 BBY, the Clone Wars erupted throughout the galaxy. Dallin, ever loyal to the Republic, stood prepared to defend Rendili against attacks from the Confederacy of Independent Systems. However, halfway into 20 BBY, the Independent Provisional Government of Rendili seized control of the planet and pledged its allegiance to the Confederacy. Dallin faced a dilemma, uncertain whether to turn his back on his homeworld and his duty as an officer or reject the Republic he loved and had fought for in the name of duty.

The Republic, well aware of Dallin's patriotism, dispatched a task force to negotiate with him. Koon, now a High Jedi General in the war, and Captain Jan Dodonna, a rising naval star and fellow veteran of the Stark Hyperspace War, journeyed to the Mersel Kebir, seeking Dallin's defection and that of Rendili's powerful Home Defense Fleet. High Jedi General Saesee Tiin commanded a task force of three Acclamator-class assault ships which would, if negotiations failed, engage Rendili's fleet.
Koon and Dodonna boarded the ship, and Dallin confessed his confusion to them; Koon advised him that his greater loyalty must lie with the Republic. Their conversation was interrupted by the ambitious Lieutenant Mellor Yago, who insisted that orders be obeyed. Dallin rebuked the junior officer, explaining that Rendili had been taken by force and that the Independent Provisional Government was merely a mouthpiece for the Separatists. Accusing Dallin of treason, Yago drew his blaster and, supported by several other junior officers, placed Dallin under arrest and assumed command of the fleet. With a knife to his neck and a blaster to his head, Dallin ordered Koon to disregard Dallin's own life and suppress the mutiny. Koon refused, stating that there would be another opportunity. Dallin, all other Home Defense Fleet senior officers, and the Republic emissaries were taken to the brig.
Yago secretly requested Separatist reinforcements while attempting to use his captives as hostages to force a Republic withdrawal. Tiin refused and instead offered Yago a chance to surrender and time to reconsider before the Jedi Master launched his attack. The Separatist fleet arrived before the last hour was up, and a battle commenced. In the brig, Koon warned Dallin and Dodonna to prepare themselves for rescue.
Jedi Masters Kenobi and Vos, Padawans when they fought alongside Dallin during the Stark Hyperspace War, infiltrated the Mersel Kebir while Jedi Knight Anakin Skywalker disabled its hyperdrive. Now free, Dallin, Dodonna, and the Jedi stormed the bridge while the other senior officers reestablished Dallin's command on the lower decks. Dallin ordered all those aboard to surrender or face immediate execution in the ongoing firefight. Wielding two blasters, Dallin had Dodonna cover him as he went after Yago. Dallin and Yago found himself mere meters from each other, each with a blaster leveled at the other. Each officer pulled the trigger; Yago missed. Dallin did not.

With Yago dead and the bridge secured, Dallin was able to quickly reassert his authority over the Home Defense Fleet. After Yago's treatment of him, he had made his decision. Dallin ordered his fleet to disengage from the Republic assault ship Sundiver and turn against the two Separatist core ships. The core ships were defeated in short order. With that done, Dallin negotiated the full surrender of the Rendili Home Defense Fleet to the Republic. The Dreadnaughts of Dallin's command were converted into prison ships for the housing of Dark Jedi.
Following the example set by the Rendili Home Defense Fleet, Supreme Chancellor Palpatine enacted a law that integrated all planetary navies into the Republic Navy. Dallin once more had the opportunity to serve the Republic directly. Fighting for the Republic Navy in the final six months of the Clone Wars, he held the rank of captain by the war's end in 19 BBY.

Concurrent with the Separatist's capitulation, Palpatine announced the establishment of a New Order, thereby changing the Republic into the Galactic Empire. Soon after this declaration, Dallin, along with numerous other captains within the newly formed Imperial Navy, received summons to Coruscant to attend an audience with Emperor Palpatine. During this assembly, Palpatine unveiled his disfigured appearance, attributing it to an alleged Jedi assault. The Jedi had been branded as enemies of the state during the transition to the Empire. Positioned in the front of the assembled captains, Dallin voiced his objection, his disbelief manifesting as spoken words. Palpatine then presented his black-clad enforcer and Sith apprentice Darth Vader to the amassed fleet, with Vader requesting Dallin to elaborate on his previous statement with utmost precision. Dallin posited the notion that some form of error or misunderstanding had transpired, referencing the commendable moral character of all Jedi he had encountered—and Vader, the very individual who, under the identity of Anakin Skywalker, had been instrumental in rescuing Dallin a mere six months prior, levitated Dallin into the air through the utilization of the Force, telekinetically constricted his throat, and subsequently propelled him headlong into the floor, resulting in his death. Vader and Palpatine desired to set an example, and Dallin unwittingly furnished them with the opportunity.
Jace Dallin's career commenced with his strong advocacy for Militarism and his support of Ranulph Tarkin and his humanocentric views. However, as he witnessed Tarkin falter under duress during the Stark Hyperspace War, Dallin's respect for the self-proclaimed General diminished. Consequently, he shifted his allegiance to Plo Koon—a non-Human—and the Jedi, impressed by their compassion for his troops and their resolute leadership throughout the crisis. Dallin disavowed humanocentrism and cultivated a profound respect for, and loyalty to, Koon and the Jedi Order in its entirety, believing that he owed his life to them. Even when confronted with Palpatine's and Darth Vader's assertions that the Jedi were traitors, Dallin earnestly defended them—an action that ultimately led to his demise.

Dallin's loyalty also encompassed the Republic. Despite his initial willingness to support Tarkin's manipulations, the sacrifices Dallin made during the Stark Hyperspace War, coupled with his subsequent change in perspective, instilled in him a deep appreciation for the Republic that he had dedicated himself to defending. He demonstrated his competence as an army commander during the war, and after sustaining facial scars while defending the Republic, he proudly bore them as "battle flags."
When Rendili declared its allegiance to the Confederacy rather than the Republic, Dallin experienced internal conflict, uncertain whether to remain loyal to his homeworld or to the Republic. He confided in Koon, who was officially an enemy of Rendili, and his ultimate decision to side with the Republic resulted in his arrest by his ambitious junior officers. After escaping and seizing control of the bridge of his flagship, he presented his mutinous crew with the option to surrender, but was prepared to use lethal force against those who resisted him—particularly Lieutenant Mellor Yago. Dallin's naval command was respected by his senior officers, and he successfully reasserted his authority over his flagship after neutralizing the treacherous Yago.
The character of Jace Dallin was conceived by writer John Ostrander for the Star Wars: Republic story arc titled The Stark Hyperspace War, in which he was visually represented by Davidé Fabbri. Dallin played a recurring supporting role in Republic, making subsequent appearances in The Dreadnaughts of Rendili and Loyalties, both penned by Ostrander. Notably, Dallin was never illustrated by the same artist twice, with Jan Duursema providing the artwork for The Dreadnaughts of Rendili and Luke Ross undertaking the task in Loyalties.
Although Dallin's eyes are consistently depicted as blue throughout the initial three issues of The Stark Hyperspace War, the fourth and concluding issue portrays them as brown, a color scheme that would be maintained in all of Dallin's subsequent appearances. This article considers brown to be the canonical color.