Battle of Yavin 4 ( Great Sith War ) The Battle of Yavin IV was one of the final conflicts of the Great Sith War in 3996 BBY . It culminated in the death of Sith Lord Exar Kun and the annihilation of much of the Massassi species on Yavin 4 . Following the defection of fellow Sith Lord and former Jedi Knight Ulic Qel - Droma , the Jedi Order and elements of the Republic Rim Fleet converged on Yavin IV — the Brotherhood of the Sith ' s main staging center . In an attempt to unleash his spirit into the cosmos , Kun used a dark side Sith ritual to drain the souls of many Massassi . However , this collided with a wall of light - side energy generated by the Jedi participants , culminating in a firestorm that devastated Yavin IV ' s surface and destroyed much flora and fauna . Kun ' s spirit survived the inferno but was imprisoned within the Massassi Temple s . Background . Exar Kun ' s program of systematic galactic conquest had claimed the lives of millions , over the years that the Great Sith War burned . With the final destruction of the great Jedi training headquarters at Ossus , it appeared that an era of self - assured complacency for the Order was now officially at an end . The need for a swift , final resolution had become all the more urgent . The Galactic Republic was dealt an unforeseen lucky break , however , when former Sith Lord Ulic Qel - Droma turned away from the darkness after slaying his own brother , imprisoned beneath a Wall of light . Ulic psychologically faced up to the consequences of his actions , realizing the need to undo the damage already wrought by his hand . Revealing the location of Exar Kun ' s main headquarters — the fourth moon of the planet Yavin — the Jedi leaders under Jedi Master Thon and Nomi Sunrider quickly organized the Republic Rim Fleet to take the war back to Kun . Conflict . Thousands of Jedi Knights from across the galaxy answered the summons , converging upon the jungle moon in a multitude of battlecraft which blotted out the sky . Looking heavenward , Kun instantly recognized Qel - Droma ' s betrayal , and vowed to continue the fight against the light by " surviving " . Some ground engagements between Republic soldier s and Kun ' s Massassi warriors occurred . Unable to counteract the Rim Fleet ' s space blockade , Kun summoned much of the Massassi population on Yavin IV to the Temple of Exar Kun for one final ceremony . Guided by ancient Sith spellbooks , he drained the Massassi of their life - essence and used the energy in a Sith ritual to free his spirit from the chains of his mortal body . For a while , it seemed that Kun would be free to ravage the cosmos forever . In response , the assembled Jedi created a massive wall of Light Side energy aimed at cleansing Exar Kun ' s corrupt presence from the galaxy and imprisoning his spirit . However , the wall unexpectedly collided and reacted with the colossal wave of dark side energy " rising " from Yavin — causing a chain reaction on the planet below , creating a massive firestorm unlike any ever seen before in history , utterly devouring all traces of Kun and the Massassi . With the holocaust proving to be unquenchable , the Jedi forces reluctantly departed from Yavin space , as the fires continued to rage out of control . Nomi , Ulic , Thon , and the rest of the Jedi were stunned at what they witnessed and asked themselves what the final cost of their actions would ultimately prove to be . Aftermath . Two years later , Qel - Droma himself would finally comprehend the cost . His newly - christened ship , " Cay ' s Dream " , landed on Yavin 4 , finding a devastated world and ecosystem , with no lifesigns anywhere to be found . No trace of Exar Kun was found and Qel - Droma left . However in the darkness of the Massassi temple , the spirit of Exar Kun screamed futile pleas for deliverance from the darkness , damned to the hell he had made for himself , but Ulic , blind to the Force , could not hear him . Gradually over the years , Yavin IV ' s ecosystem regenerated and recovered till it could sustain flora and fauna again . Some Massassi on Yavin IV , including Kalgrath , also survived the firestorm . Over the centuries , their numbers on Yavin IV multiplied . In 3756 BBY , these Massassi were encountered by the covert True Sith spy Barel Ovair and the Jedi Padawan Eison Gynt who were on a mission to ostensibly eliminate the dark side energies emanating from the tomb of the Sith Lord Naga Sadow from the Great Hyperspace War . These Massassi attacked the two offworlders and drove them deeper into the tombs where they encountered the Sith Lord ' s lingering energies . Seven years later , Gynt emerged wearing Massassi warrior robes and possessed by Sadow ' s dark side spirit . Gynt attacked master Ovair in broad daylight in Coruscant but was bested by Ovair . In addition , there were Massassi living on other worlds including Korriban and Tund . Nearly four thousand years later in 1 ABY , Professor Walter Emanus led a Corellia University archaeological expedition . However , during their excavations , they uncovered the catacombs beneath the Dark Lord ' s temple and reawakened his spirit . He possessed them and made them into the Cult of Exar Kun , which was devoted to his worship . Under his influence , some of the cultists traveled to the Corellia University research outpost on Talus to recruit more students and researchers to their ranks . The cult based itself around the catacombs , but was destroyed when Professor Cornelius Wagglehorn , a former colleague of Emanus , hired a group of spacers to drive them out . Kun himself battled the spacers , but due to his spirit form , was easily defeated and silenced once more . In 11 ABY , Kun ' s temples became the site of Luke Skywalker ' s Jedi Praxeum , a school where he began the re - creation of the Jedi Order . The Jedi trainees ' exercises in the Force awakened Kun who sought to subvert the Jedi training . As a spirit , Kun appeared to the young Jedi apprentice Gantoris . The inexperienced apprentice was unable to avoid being corrupted and , when he started to resist , Kun killed him , burned from inside . After destroying his first Jedi in thousands of years , Kun ' s insatiable appetite for spreading his dark wrath escalated . He was able to successfully corrupt and partly possess the young and extraordinarily talented Kyp Durron . In addition , he sundered Skywalker ' s spirit from his body , demoralizing his Jedi apprentices . Kun ' s spirit was eventually roused from hiding and banished into Chaos by the combined efforts of the Jedi apprentices , Luke ' s spirit , and the long - dead spirit of Kun ' s Master , Vodo - Siosk Baas . After Kun ' s shade was vanquished , Corran Horn destroyed Kun ' s temple with proton torpedoes , thus eliminating his dark taint .