Great Galactic War The Great Galactic War , known as the Great War during the conflict and in the years afterward , was a war between the Sith Empire and the Galactic Republic between 3681 BBY and 3653 BBY , lasting for a total of 28 years . Also known as the Republic – Sith War , the conflict was ultimately the culmination of a 1300 - year grudge held by survivors of the old Sith Empire against the Republic for their defeat in the Great Hyperspace War . The war would cost countless lives and devastate worlds from the Core to the Rim , as well as having dramatic galactic consequences otherwise . The Republic economy was shattered and roughly half the galaxy would end up under Sith dominion , and the Jedi Order would withdraw from the galactic capital to establish a new home on their ancient homeworld . But it would not ultimately be conclusive . While a strategic defeat for the Republic , the end of the war left both powers standing , engaged in an undeclared conflict for supremacy on numerous disputed worlds . Background . With the Sith Empire ' s defeat in the Great Hyperspace War , the Republic decided how to deal with their fallen enemy : Supreme Chancellor Pultimo ordered the Republic Military to exterminate all remnants of the Sith . But one Sith Lord and a group of survivors escaped the Republic ' s slaughter of their kind and fled to the Unknown Regions . There , he re - founded the Empire , assumed the title of Sith Emperor , and created a council of other Sith Lords to rule under him . Using the power of the dark side , the Emperor kept himself alive for over a thousand years after the Great Hyperspace War , rebuilding the Empire ' s strength and promising his people revenge on the Republic and Jedi . The Republic , meanwhile , was challenged in a number of wars over the next few thousand years . After the war with Exar Kun , the growing Sith Empire goaded the Mandalorians to attack the Republic . A group of Jedi , led by Revan , soon joined the Republic forces in their war against the Mandalorians . During the war , Revan traveled to the ancient Sith academy on Malachor V , where the final battle of the Mandalorian Wars would later take place . During his time there , he learned of the true Sith ' s existence in the Unknown Regions . He then used a Rakatan artifact to start a war with the Republic to prepare for the Sith Empire ' s invasion , resulting in the Jedi Civil War . The Republic was also burdened by the upheaval of the Kanz Disorders . The Sith Empire prepares for war . The Sith Emperor had ordered preparations for an invasion of the Republic as early as 3954 BBY , nearly three centuries before the war began . Four years later , these initial plans were delayed thanks in large part to the efforts of the legendary redeemed Jedi , Revan . But the Empire would not be dormant in the following years . The Emperor ' s war preparations continued nonetheless , with only the timing of invasion postponed . Two and a half centuries of military build - up would happen before a shift to direct preparations for invasion . After such a lengthy build - up , the Sith fleet had grown to enormous numbers ; and now Imperial agents had begun to operate in secret , arranging alliances both within and outside of Republic space . Imperial operatives were successful in securing an alliance with the Chiss Ascendancy , as well as installing puppet governments in key positions in the Republic ' s Outer Rim systems . Before a shot had been fired , the Empire had already secretly brought the Belkadan , Ruuria , and Sernpidal systems of the Dalonbian sector under its control . These would prove to be vital assets for the Empire in the early days of the war . As invasion drew nearer , the Imperial Navy ' s war games would reach fever pitch — military exercises became a daily event . On the eve of war , the Imperial fleet gathered in key staging locations just outside of Republic space , and in the year 3681 BBY , the Sith Emperor ordered the invasion of the Republic . War . Return of the Sith . Fall of Korriban . For centuries , the ancient Sith homeworld Korriban had been guarded by a vigil of Jedi and a fairly small contingent of Republic trooper s . At the onset of the war this garrison was overseen by Jedi Master Kao Cen Darach and his Padawan Satele Shan . In a move which caught the Republic defenders completely by surprise , a Sith fleet of over 30 warships launched a massive assault on their long - occupied holy world Korriban . The Republic and Jedi defenders quickly fell to the Imperial attack , while Sith Lord Vindican and his apprentice Malgus battled Jedi defenders Darach and Shan on the orbital station . Shan escaped the fighting on orders from her master , but Darach was slain in a lightsaber duel by Malgus . With a minimal effort due to overwhelming force , Korriban was captured by Imperial forces and brought under Imperial dominion once more . The attack was so successful that an extended period of time passed before the Jedi Council even learned of Korriban ' s loss . Skirmish in the Tingel Arm . As yet unaware of the fall of Korriban , the appearance of Imperial battlecruisers in the Tingel Arm and Aparo sector was a mystery to the Republic . Naively hoping to resolve the unexpected situation quickly , the Republic dispatched a lightly escorted diplomatic team to find out what was happening . The Emperor saw this as an excellent opportunity to begin a campaign of psychological warfare . The Imperial fleet waited for the Republic ' s diplomatic team to come to them , and then allowed just enough time to transmit images of their armada back to their superiors before utterly destroying them . In response to the threat , the Republic immediately mobilized a fleet to the besieged area in the Tingel Arm . Arriving in proximity to Belkadan , Ruuria , and Sernpidal , the first Republic war fleet found itself ensnared in the Empire ' s trap . Surrounded by Imperial warships and turncoat allies , the Republic fleet was forced to scatter and retreat to Mirial in order to avoid complete annihilation . Destruction of the Sluis Van shipyards . With the capture of the Tingel Arm and the rout of the Republic forces there , the Sith Empire turned its sights on a valuable new target : the Sluis sector . Sluis Van was the home of significant Republic starship manufacturing facilities which presented a tempting target for the invading Imperial forces . The Imperial naval forces quickly moved on Sluis Van , which was entirely undefended with the Republic forces still scattered . Various Sith starfighter squadrons attacked the shipyards and destroyed the orbital ring that made up the station . The Sith forces continued to press , and conquered the world itself . Much as would continue to be the case as the war pressed on , the Imperial forces executed any civilian or government workers who refused to swear fealty to the Empire . The token Republic military personnel were not granted such mercy , they were simply hunted down and summarily executed as enemies of the Empire . Republic response . Despite the violence of the attacks , not all Senators were convinced of the threat they faced . Some in the Senate argued that the attackers were simply another upstart species who could be defeated if only the military could devise an effective strategy . While this faction did not " control " the Senate , it was enough that the body was paralyzed by indecision . The Jedi , by contrast , took more decisive action . As the ancient enemies of the Sith , the Jedi Order recognized the threat for what it was and dispatched a force to attempt to defend the Minos Cluster . The Jedi hoped that their action would spur the Republic into action , and indeed they were successful in doing so . After witnessing the heroism of the Jedi on the news feeds , lines began to form at countless recruitment centers across the Republic . As the public clamored for action , the Senate came together and began proper planning for war . Though having already faced a number of defeats , the Republic rallied to defend itself from the attack . Even as the Senate and populace prepared , the Jedi forces already active in the Minos Cluster dug into defensive positions on several worlds , including Eliad . Even as the struggle for Minos continued , the Republic attempted to counterattack in the Seswenna sector . The Empire had blockaded the Rimma Trade Route there , strangling the flow of supplies to Republic troops at Minos . While the initial attack was unsuccessful , the Republic fleet was able to regroup and break the blockade , allowing much - needed supplies to resume traveling to the besieged Minos Cluster soldiers . Battle of Korriban . Three years into the war , in 3678 BBY , a rogue Sith apprentice leaked information on Imperial fleet movements to the Republic . In truth , Kressh was only interested in causing the battle in order to create a diversion so that she could pursue her own personal goals . Republic forces moved quickly to attack the Sith ' s holy world . A battle erupted in orbit between the invading Republic forces and the Sith garrison of starships left to guard the planet . But the Republic ' s first counter - offensive quickly turned into a rout , and then a crushing defeat . The Republic invasion force was overwhelmed by the Sith defenders and crushed , leaving only prisoners and the dead . Battle of Balmorra . Balmorra , a world renowned galaxy - wide for its droid - and military - manufacturing capabilities , was targeted for conquest by the Sith Empire early in the war . An invasion soon followed . Shortly after the invasion began , the native Balmorrans organized a resistance group to defend their world . The Republic soon recognized the threat of the Empire controlling the manufacturing capabilities of Balmorra and launched its own counter - attack as well . The struggle would become the most protracted and enduring of the entire war . Though the Republic would eventually be forced to reassign its military assets to other fronts in the war , the Balmorran resistance would maintain the fight throughout the decades of the war and even into the Cold War . Battles for the Outer Rim . The Sith went on to seize many worlds in the Outer Rim and the rich resources of the Minos Cluster . Battlegrounds included Ilum , Dathomir , and Manaan , the latter seeing its surface cities destroyed , despite attempts to remain neutral . The Republic was further defeated at Agamar and Utapau . After nearly a decade of fighting , Republic Intelligence estimated that the Empire controlled nearly half of the Outer Rim . Stalemate . Republic victories at Bothawui . After a decade of conquering the Outer Rim , ending with the capture of the Seswenna sector , the Sith advanced moved toward assaulting the Mid Rim . Believing the Republic was still recovering from its losses , the Empire rashly sent an invasion force to the planet Bothawui . However , for the first time since the war started , the Republic was well - prepared for defense . Admiral Greik had anticipated the attack and , in a risky maneuver , gathered the entire Republic fleet over Bothawui . The Imperial attackers were caught completely off guard and utterly obliterated at the First Battle of Bothawui . Though it had taken ten years of defeats , the Republic had finally claimed its first significant victory over the Imperial war machine . The news of the victory proved a great boon , rekindling hope and generally increasing morale throughout the besieged Republic . The sweetness of victory , however , would be short - lived . Seeking vengeance for their humiliating defeat , the Empire sent a much larger force back to Bothawui . With powerful planetary shields in place , the Republic defenders , led by Jedi Master Belth Allusis , were able to force the Imperial forces into a ground battle . An Imperial army of 50 , 000 soldiers descended on the planet and engaged in one of the bloodiest battles of the war . Imperial forces lost , on average , 10 soldiers for every one of the Republic ' s they killed . While the Imperial commanders were forced to call for reinforcements due to the losses , the Republic defenders stood defiant to the last man – despite an offer of safety if they were to surrender . The Imperial victory was Pyrrhic . While they succeeded in destroying the Republic forces , Master Allusis and his forces inflicted such damage on the invading Imperials that they were forced to retreat . The Second Battle of Bothawui was ultimately a draw in terms of material gain and loss , but the heroic sacrifice of Allusis and his troops gave Republic troops galaxy - wide a memory around which to rally . In retrospect after the war , scholars such as Master Gnost - Dural would come to identify the victory at Bothawui as the only eventual outcome of the war ; that the Republic ' s only hope in the face of the Sith onslaught was survival , not victory . Capture of the Dread Masters . In 3668 BBY , Republic warships began mysteriously disappearing by the dozens . Investigations by the Republic SIS learned that a group of Sith known as the Dread Masters were using a form of battle meditation to project terror on the crews of Republic ships , making them flee in fear . For thirteen years of open warfare , the group avoided compromise by consistently being on the move aboard an Imperial dreadnaught . But after learning of their existence , an elite Republic strike team led by Jedi Knight Jaric Kaedan was able to infiltrate the Dread Masters ' ship and capture them , as well as gathering valuable intelligence from the dreadnaught ' s computers before destroying the ship . The Republic announced publicly that the strike had killed the Emperor ' s valued agents , but they had secretly spirited away to the Republic prison planet Belsavis when the Jedi learned that the Dread Masters were centuries old and decided they were too valuable to simply execute . The group of dangerous Sith Lords had been removed from the conflict , and would not be an operational threat to the Republic for the remainder of the war . The intelligence obtained in the Dread Masters mission would prove enlightening to both Republic Intelligence and Jedi scholars alike . The war had been on for 13 years and the Republic finally learnt that the Imperial capital was situated on Dromund Kaas , a world unknown even in the Jedi Archives . The Jedi also learned that the Sith Emperor was , as had been rumored , many centuries old and a survivor of the original Sith Empire . Battle of Alderaan . Alderaan was a world renowned as the embodiment of all the principles upon which the Republic rested . This , paired with its being located in the Core , made it an ideal target for the Imperial advance . Not only would it be a key strategic position within the Core , the capture of Alderaan would be a crushing blow to Republic morale . The mission to conquer Alderaan was spearheaded by Malgus , by that point a seasoned veteran of the war , and recently granted the title of Darth . After luring Alderaan ' s Republic defense fleet away from the world , Malgus and his army unleashed their attack , hoping for a swift victory . Malgus was not aware , however , that the Republic had a sizeable garrison of troopers on the planet surface . In addition to being a stopover rest point for soldiers traveling from the Rim back to the Core , the elite Havoc Squad was on the planet as well . As on countless other worlds over the past 14 years , a desperate struggle for control of the planet erupted . The Imperial advance claimed some key early victories , such as the capture of the Alderaanian royal family , and set its sights on seizing the planet ' s capital city . In one of the planet ' s many lush forests , the force being personally commanded by Malgus was set upon by Havoc Squad . The skirmish initially appeared to be an Imperial victory , until backup led by Jedi Satele Shan arrived . Shan and Malgus dueled once more , more than a decade after their first encounter above Korriban , while Republic and Imperial troops fought each other for survival and control of the planet . Shan and the Republic troops ultimately proved victorious , driving the invading Imperial army from the planet and critically wounding Darth Malgus in the process . Despite his injuries , Malgus escaped from the planet as well , but the hour was the Republic ' s . In the months after the victory at Alderaan , the Republic scored a string of victories , including the liberation of a number of systems in the Mid Rim as well as regaining a foothold in the Minos Cluster . New strategies . With the defeat at Alderaan and its advance toward the Core seemingly stalled , the Empire began working on a new tactic to employ . Operatives of the Imperial intelligence service recognized the potential of bringing a powerful ally into the war and set to work on recruiting them . In centuries past , the Emperor had used the Mandalorians to attack the Republic , and the opportunity presented itself once more . Imperial agents selected a powerful combatant on Geonosis and did everything in their power to aid in his rise , engaging in activities from gladiator management to outright poisoning of his opponents . As this warrior ' s star was in ascendance , Imperial agents began to spread the idea that he could be the new Mandalore and unite the scattered clans . Their plan proved fruitful , and this warrior was able to establish himself as the galaxy ' s most powerful warrior and claim the title of Mandalore – though at some point , he became a willing servant of the Empire . As the war approached its third decade , both Republic and Empire also sought to gain advantage by debuting powerful new starships and experimental superweapons . In 3665 BBY , 16 years into the war , the two militaries clashed over Hoth . Many starships from both sides were destroyed in the battle , including one carrying captured Jedi Master Wyellett . Much of the wreckage rained down on the frigid planet below , providing fertile pickings for pirates in the years to come . The battle was particularly devastating to the Republic Navy , which had still not fully recovered three years later when the Mandalorian blockade began . The Mandalorian blockade . After uniting the scattered Mandalorian clans , the new Mandalore encouraged his followers to make war upon the Republic and confront the greatest challenge of all — fighting the legendary Jedi Knights . Following orders from his Sith superiors , he ordered the Mandalorian fleet to blockade the Hydian Way , the Republic ' s most critical trade route . With the Mandalorian blockade in place , the Republic found themselves with no raw goods or supplies to feed the countless trillions of sentients in the Core Worlds . After several pleas from the Republic , a Jedi attack attempted to break the blockade , but was soundly defeated and forced to retreat to Devaron . The Mandalorians continued the blockade , denying the Republic raw goods and handicapping the Republic ' s war effort . Eventually , riots broke out on Coruscant , and the Senate began to discuss the possibility of surrendering to the Sith . An unlikely hero proved the savior of the Core Worlds . Hylo Visz , a smuggler motivated by the possibility of great profit in a time of dire need , organized a smuggler fleet to defeat the blockade and enrich herself in the process . After loading up large freighters with resources from the Outer Rim , Visz moved them to approach the blockade and hold position close by . The Mandalorians ' hails went ignored and so they moved to attack the freighters , and Visz ' s trap was sprung . A fleet of smuggler starships dropped out of hyperspace behind the Mandalorians and began laying waste to the blockade . The Republic SIS , who had been monitoring the situation , rushed Republic and Jedi ships in to assist in the fight . The Mandalorian blockade was broken , and whether during the attack or shortly afterward , Mandalore was slain . Though a new Mandalore of uncertain allegiance took his place , the Mandalorians ceased to be a military threat to the Republic for the remainder of the war . Battle of Ord Radama . Sometime later , Imperial forces commanded by Darth Venemal and Malgus attacked Ord Radama in the Outer Rim . The assault was an initial success , as the Sith led their forces to capture the planet ' s capital city . " Holding " their conquest , however , would prove to be much more challenging than capturing it had been . Weeks went by with no resupplies arriving for the Imperial forces . Eventually Republic reinforcements arrived in orbit and destroyed the Imperial fleet tasked there . Damage taken by one of Malgus ' " Harrower " - class Dreadnoughts sent it plummeting into the planetary atmosphere , and it crashed into the capital city – destroying it utterly . With Republic victory certain and Darth Venemal killed , the Sith forces withdrew . Republic counter - attack . After the Republic victories over the Mandalorian blockade and at Ord Radama , Republic forces pressed the advantage back into Imperial - held space . Republic strike groups made attacks on Korriban , which Malgus believed to be only feints , while a larger Republic fleet amassed over the Imperial world Ziost . Republic forces laid siege to the planet , hoping to establish an important foothold inside Imperial space . The Ziost system was within striking distance of the very heart of the Empire ; both Korriban and the capital world , Dromund Kaas . After several months of fighting , Imperial forces regained the upper hand and forced the Republic off the planet . The Imperial advance continues . With Ziost defended , the Empire once more turned back on the offensive . Malgus , personally guaranteed by the Dark Council to never again face supply shortages , turned his attention on the Outer Rim world Serenno . Malgus had learned from Imperial Intelligence that a Jedi Master , Ven Zallow , and his contingent had established themselves there . It was feared that Serenno was a staging ground for establishing a more strategic position , and so Malgus ordered one of the Empire ' s infiltrators , a high - ranking noble , to do his bidding . Malgus prepared to use his new agent to assassinate Zallow and begin the Jedi ' s undoing on Serenno . Moving quickly , Malgus ordered his agent to strike while he mobilized the Imperial fleet under his command . The mission was a partial victory . Zallow had slain the infiltrator and escaped on one of the Republic ' s ships , but Serenno had been taken with a minimal of effort and resources expended . Serenno did not welcome the Imperial presence , but Malgus soon put an end to any thoughts of rebellion . Assassins supplied by the Dark Council were unleashed upon the world , and massacred all those who would dare to defy Imperial rule . A few short months later , Malgus was ordered by the Sith Emperor to recapture Ord Radama and avenge the previous Imperial defeat there . Leaving nothing to chance , Malgus decided to personally command a regiment of Force - strong combatants as they moved on the planet ' s new capital city , New Raido . The battle dragged on for months , more bloody than the first time the powers had clashed over the planet . Jedi traps repeatedly confounded Imperial efforts , while Malgus enjoyed the bloodbath of wholesale slaughter of both sides . Near the end of the war , Rhen Var was invaded by Imperial forces under the command of the Sith Lord Darth Mekhis . The swift invasion took the world by storm and the Imperial forces devastated the troops of the Republic . Imperial victory there , however , would ultimately prove to be short - lived . The remaining Republic troops were rallied by a group of Jedi led by Satele Shan , and drove the Imperial forces back in one of the Republic ' s last victories of the war . Sacking of Coruscant . With the Sith Empire ' s military advance toward the Core halted , Imperial tactics became far more aggressive and desperate as the war entered its third decade . Seven years after the defeat of the Empire ' s Mandalorian allies at the Hydian Way , the Dark Council stunned the Republic by offering the chance to negotiate a peace treaty . Fearing a ruse , the Jedi Council formally recommended that the Senate ignore the overture , but they were ignored . However , Senators and Jedi alike did agree that the war could not be won and that , if nothing else , peace negotiations would offer their war - weary troops a respite . At the Senate ' s request , Grand Master Zym agreed to send a contingent of Jedi with the peace delegation , and diplomats from both sides traveled to Alderaan to discuss terms . But the Empire ' s peace overture was indeed a deception . Even while Republic and Imperial negotiators talked on Alderaan , a large Sith fleet invaded and sacked Coruscant itself , the heart of the Republic . As a team of Sith warriors led by Darth Malgus attacked the Jedi Temple and slaughtered all within , the fleet , led by Darth Angral , bombarded and invaded the planet . Once Coruscant ' s planetary defenses were destroyed , the Sith destroyed the Jedi Temple outright and blockaded the planet to hold its inhabitants hostage . With the galactic capital firmly under Sith control , Angral traveled down to the surface and stormed the Senate Building himself . Once inside , he personally executed Supreme Chancellor Berooken and claimed the office as his own command center for the duration of the occupation . Treaty of Coruscant . Faced with no alternatives , the Republic diplomats on Alderaan were forced to agree to the Treaty of Coruscant . The treaty mandated that all Jedi and Republic forces stand down from combat duties and withdraw into Republic space . It also demanded that the Republic recognize the Empire as the legitimate ruler of half the galaxy , and that the Republic cede to the Empire a number of worlds that had not been conquered by Imperial forces . While the Republic still stood , the Sith Empire had claimed decisive victory in the war . Aftermath . The treaty forced the Republic to give up many outlying systems to the Sith Empire . However , there were forces in the Republic that didn ' t accept the treaty . There were Republic troops , namely on Dantooine and Balmorra , who refused to withdraw and mutinied to continue the war while another group within the Republic , led by the Jedi Master Dar ' Nala , bombed the Senate building to assassinate the Senators who supported the treaty , believing them to be Imperial spies , while also planning on ruining the treaty . Dar ' Nala also orchestrated a supposed Sith attack on the " Envoy " in an attempt to neutralize the treaty . However , when Dar ' Nala attempted to put the last phase of her plan into action , her madness was revealed to her supporters and they abandoned her , which led to her death . The peace held through after this . Although his Empire was stronger than ever , the Sith Emperor no longer seemed to desire total conquest . He handed over control of the Empire to the Dark Council , who would oversee the day - to - day affairs of state , and went on to pursue his own mysterious goals as the Sith consolidated their power . By the end of the war , thousands of Jedi were dead . The Galactic Republic focused its anger on the Jedi , blaming the Order for its defeat at the hands of the Sith . Though they were still committed to defending the Republic , the surviving Jedi chose to return to their ancient homeworld of Tython in order to rebuild their strength . The end of the Great Galactic War set the stage for a Cold War between the Sith Empire and the Galactic Republic in the years that followed . The Cold War saw a number of border skirmishes and proxy wars , eventually pushing the two superpowers back into open war . Behind the scenes . The term " Great War " is an obvious reference to the real - world , which used to be the most common nickname for World War I in the . After the term fell into disuse though it is still used in historical discourse .