Battle of Rhen Var
The Battle of Rhen Var represents a significant clash during the Great Galactic War, pitting the forces of the Galactic Republic against the reconstituted Sith Empire. This battle unfolded in the concluding years of the war, prior to its resolution in 3653 BBY. The conflict was sparked by the Empire's strategic move to invade and capture Rhen Var, an icy world situated in the Outer Rim. This operation was under the direct command of Darth Mekhis, a Dark Lord of the Sith and a member of the Dark Council. Mekhis, a Sith scientist renowned for her expertise in alchemy, sought to exploit Rhen Var as a testing ground for her novel creations. While her initial efforts proved fruitful, the Republic responded by dispatching an intervention force, composed of members of the Jedi Order, to contest the Empire's dominion over the planet.
The Republic's defensive contingent, under the leadership of Jedi Knight Satele Shan, confronted the Imperial Army on Rhen Var. They systematically pushed forward towards Darth Mekhis's headquarters. Despite the substantial losses endured by the Republic Army during the engagement, Shan, alongside fellow Knights Syo Bakarn, Jaric Kaedan, and Bela Kiwiiks, successfully galvanized their troops and maintained their offensive. Following an extended series of skirmishes within Rhen Var's frozen forests, Shan personally breached Mekhis's stronghold, confronting the Dark Lord in a fierce duel. Shan emerged victorious, inflicting a significant wound upon the Sith and securing a crucial win for the Republic. While the Republic sustained considerable casualties, the triumph on Rhen Var effectively checked the Empire's progress and offered a temporary shift in momentum during the Great Galactic War.
Prelude
The Battle of Rhen Var transpired between 3660 BBY and 3653 BBY, marking its occurrence in the final phase of the twenty-eight-year Great Galactic War fought between the Galactic Republic and the reconstituted Sith Empire. This war engulfed numerous star systems and witnessed the ancient democracy facing numerous setbacks as it struggled to impede the Sith advance. Following notable military defeats on battlegrounds such as Korriban, the Minos Cluster, and Begeren, the Republic appeared to be on the brink of utter destruction. However, an unexpected victory in the second battle at Bothawui served as a rallying point for the Republic's defenders and the Jedi Order, enabling them to achieve a series of triumphs that stalled the Imperial Military's offensive.
Simultaneously, the Sith Emperor and the Dark Council felt increasing urgency to bring the protracted war, which had already stretched beyond a decade, to a swift conclusion. Around 3667 BBY, the Empire initiated an aggressive campaign aimed at the Core Worlds, encompassing an invasion of Alderaan and the blockade of the Hydian Way, while simultaneously maintaining their offensive in the Outer Rim. The Empire's endeavors in the Core Worlds encountered substantial resistance, depleting their war funds and straining their military capabilities. Nevertheless, the Empire persisted with its strategy, seeking to reinforce its stretched forces by seizing additional worlds in the Outer Rim to procure essential resources and slaves. As the war approached its third decade, Darth Mekhis, a Dark Council member and a proficient Sith scientist and alchemist, turned her attention to Rhen Var, located in the Thanium Worlds within the Outer Rim Territories. Her objectives were to secure the world for the Empire, exploit its resources for the Sith war effort, and utilize it as a testing ground for her recently developed weaponry.
The battle
Darth Mekhis spearheaded her invasion force to Rhen Var, establishing her command center within a mountain fortress complex. While she oversaw the development of advanced weapons technology within the compound, her division of the Imperial Army was commanded in the field by a troop commander and Colonel Rymar Quinn, tasked with securing the planet for Mekhis's purposes. Comprising assault droids, Imperial soldiers, and Sith Warriors, the invasion force initially achieved considerable success, gaining control over a significant portion of the planet's frozen terrain for their master's use.

However, this dominance faced a challenge with the arrival of the Republic's army under the joint leadership of four Jedi Knights: Syo Bakarn, Bela Kiwiiks, Jaric Kaedan, and Satele Shan, all former apprentices of the Jedi Master Ngani Zho. Shan directed the Republic's defense, navigating the snowy landscape and engaging the Sith forces. The Republic's Forty-fifth Battalion, accompanied by their Manka-class armored transports, served as a scouting element for the Jedi and the main army. Bakarn, a skilled Jedi healer, focused on healing the injuries sustained by Republic soldiers, while Kiwiiks provided tactical expertise. Kaedan and Shan, both exceptional combatants, fought on the front lines against the Empire's forces.
During a scouting mission in the forests of Rhen Var, the Forty-fifth Battalion was ambushed by the Empire, which deployed weaponized poison gas. The scouts were either killed or incapacitated before the Jedi and Republic reinforcements could reach them. As Bakarn attempted to alleviate the suffering of the dying scout Maxin Davers, Kiwiiks and Kaedan deliberated on the impending Imperial onslaught and the feasibility of maintaining their position. Shan, overhearing their discussion, intervened to assert that they would not only hold their ground but also advance towards Darth Mekhis's fortress. In the ensuing conflict between the Republic forces and the Empire's legions, the Jedi and their soldiers clashed with numerous Imperial troops and Sith. Together, the four Jedi overcame their adversaries, leading their forces forward.
As the Republic forces initiated their siege of Darth Mekhis's stronghold, the Dark Lord received a communication from her field commander, reporting that a five-minute battlefield projection indicated 600 Imperial casualties, but that Rhen Var remained under their control. Upon receiving this information, Mekhis activated her experimental chaosphere and necroswarm colony weapons, instructing the commander to deploy them to annihilate their enemies. Despite the apparent advantage for the Sith, Shan breached the compound, defeating all of Mekhis's defenders before reaching the Dark Lord's command center. After blasting through the barrier doors, Shan confronted and engaged Darth Mekhis in a duel. Shan ultimately triumphed, wounding Mekhis and securing a Republic victory on Rhen Var. The Bane Brigade, an Imperial unit notorious for war crimes in the eyes of the Republic, participated in the Battle of Rhen Var and suffered significant losses, although some members survived.
Aftermath

The Battle of Rhen Var emerged as a pivotal engagement in the war, marking a turning point for the Republic. The successful defense of Rhen Var, mirroring the earlier triumph on Alderaan, significantly boosted morale, enabling the Jedi and the Republic Military to effectively counter the Sith's advance and impede the Empire's progress. However, this victory on the icy world came at a steep price, requiring three full days for memorial droids to recite the names of all Republic casualties. Furthermore, the failure of the Sith invasion forces only intensified the Emperor's and the Dark Council's determination to conclude the war, driving them to devise the battle plans for their ultimate offensive: the Sacking of Coruscant. The ensuing Treaty of Coruscant brought the war to an end, but solidified the Empire's position as the clear victor.
Although Imperial Colonel Rymar Quinn perished during the conflict, Darth Mekhis survived the battle, continuing her service on the Dark Council for many years. She played a crucial role in the formulation of the Treaty of Coruscant, while harboring a deep-seated animosity towards the Jedi, particularly Satele Shan, the opponent who had defeated her on Rhen Var. Shan, Bakarn, Kiwiiks, and Kaedan all continued their distinguished careers as Jedi, eventually attaining the rank of Jedi Master. By the later stages of the Cold War, all four Jedi served on the Jedi High Council, recognized as heroes of the Great Galactic War.
Behind the scenes
The Battle of Rhen Var was initially presented in The Old Republic—The Lost Suns 1, the inaugural issue of the Star Wars: The Old Republic—The Lost Sunscomic series, authored by Alexander Freed and published by Dark Horse Comics on June 8, 2011.