The Sith are an order of Force practitioners who have chosen the dark side of the Force as the source of their power. Members of the Sith Order are called Sith Lords or Dark Lords of the Sith. The sworn enemy of the Jedi, the Order has existed in many forms and structures throughout history. Originally, the Sith were a humanoid species, enslaved by a group of exiled Dark Jedi. These renegades came to call themselves the Lords of the Sith, or simply Sith. The goal of the Sith was to conquer the Galactic Republic and exact vengeance on the Jedi Order.
Rather than accessing the power of the Force through inner peace, the Sith have learned to tap the power of the Force by giving into extreme emotion. By letting feelings like anger or fear take over, the Sith can use emotion as a conduit to channel the power of the Force.
There is a common misconception that the Sith access the Force through evil or that being a Sith Lord automatically means that you are evil. This is not true. Any extreme emotion can access the Force. The essence of the Sith's power is in passion, not evil. Passion can take the form of joy or love as well as anger or hatred. Sith are typically evil in that they are often blinded by their passion or corrupted by the power granted to them by the Force.
This plays into the second major difference between the Jedi and the Sith. The Sith believe the Force is a tool to be used and that the power in and of itself is justification enough for their actions. In short, they believe they can do anything they want simply because they have the power to do so.
Differences aside, the Jedi and Sith share a common lineage, and the origin of the Sith Order starts in the very halls of the Jedi Council.
Sith only operate in pairs -- one master and one apprentice. Though it was not always so, under the current doctrine of the Order there can only be two Sith Lords at any given time. This doctrine was put in place by a legendary Sith Lord named Darth Bane. Bane did this to prevent the destructive infighting that plagued the Sith Order for millennia. With this system, Dark Lords pass the Sith legacy through the generations in an unusual and violent way.
After years of working together, an apprentice will kill his master when he senses an opportunity to become the master himself. This new master then takes an apprentice of his own. Of course, should the apprentice fail to kill his master, he will surely be killed in retaliation and the master will find a new apprentice. This method uses the Sith Lords' innate ambition to make sure that only the strongest Sith survive.
Unlike the Jedi, who use their own names, Sith Lords take a title that starts with Darth (the ancient Aurabesh pronunciation for the word for "dark") and that ends with a name of their master's choice, such as Darth Vader or Darth Plagueis. This was not always the case with the Sith. It's a system used by modern Sith Lords to hide their true identities.
Like the Jedi, the Sith are skilled in the art of lightsaber combat. Some of the most legendary Force swordsman have been Sith Lords. In recent history, Darth Maul was considered one of the most talented and savage warriors ever to wield a lightsaber. Maul used a custom-built, double-bladed lightsaber and could easily fight several Jedi at once.
In the Jedi Order, each Jedi student makes a journey to get Ilum crystals for the lightsaber they will one day build. This journey is considered a rite of passage. As a result, Jedi lightsabers are blue, green, or the very rare purple depending on the crystals they find.
There is no such ritual for the Sith. The Sith prefer synthetic crystals for their lightsabers. The synthetic crystals save the Sith the long trek to get Ilum crystals, provide more blade tuning options, and give Sith lightsabers their characteristic red blade.
After thousands of years and many wars, the modern Sith Lords have learned to use deception and subterfuge rather than outright warfare to further their quest. This shadowy, manipulative approach is what ultimately led the Sith Order to destroy the Jedi Order and take over the galaxy during the rise of the Galactic Empire. But as with all things, none of this would have been possible without the boundless power afforded to them by the Force.
The tenets of the sinister order were cunning, stealth, subterfuge and most of all, a virtue borrowed from their worst enemy, patience.
The Sith believed that the true power of the Force lay not through contemplation and passivity, but rather by tapping into the emotion-filled and hateful energies of the dark side. They believed it was their passion for things—anger, hatred, fear—that fueled their power of the Force. The Sith desired to become stronger, both as individuals and as an organization, so they could achieve a higher potential of being. They compared the passive teachings of the Jedi to the actions of shepherds, while the Sith themselves were seekers of true knowledge and power.
Improvement through conflictEdit
The Sith philosophy pointed out that it was conflict that lead to the improvement of both individuals and civilizations, because it encouraged people to better themselves. Conflict forced change, growth, adaptation, and evolution. Conflict ensured that the strongest survived. This could be seen throughout the galaxy, as stronger organisms flourished and weaker ones died off. The Sith believed that this same philosophy, one not invented by them but used by the universe itself, was the path towards true perfection. Without conflict there would be only stagnation. They saw the teachings of the Jedi as a crux that prevented change and improvement.
The Sith believed that any opportunity, even an unsure one, must be snatched. They believed that beings only deserved what they were strong enough to take and protect, and that those too weak to stand against the strong deserved their fate. The way of the Sith was for the pupil to outshine the master and the stronger Sith to take the lead, often through the destruction of one former partner. Some, but not all, Sith believed that morality was but an obstacle to overcome, because it got in the way of a Sith's ability to recognize and grasp opportunities.
Some Jedi who left the Order to join the Sith felt that their mettle and worth was tested far more often as a Sith than as a padawan learner, and that this made them stronger in a shorter amount of time.
It is interesting to note that use of the dark side of the Force sometimes left the user horribly disfigured. Some Force users argued that this was because the dark side corrupted those who use it, as it was an improper use of the Force, but a few Sith believed that the true power of the Force was simply too much for mere mortal bodies to withstand, and took disfigurement as a sign of their increased capability.
The Sith did not think of emotions as a negative force but rather a tool or path to power. Whereas a Jedi would teach that fear was a negative emotion that must be overcome, a Sith would point out that every living creature was subject to fear, and that without feelings of fear that told it to run or feelings of anger that told it to fight the creature would probably die. The Sith did not consider themselves beyond the need of simple passions, but recognized the key role certain passions played in channeling the power of the Force.
The Sith felt that Jedi teachings treated the Force as a burden where users must guard against weakness and evil. The Sith preferred to think of the Force as a gift. They celebrated the Force and used it to acquire power over others because they felt that was how the Force was meant to be. The Sith challenged and embraced the passions that lay within them and used them to realize their true potential. Many Sith described this goal as "being what they were meant to be."
Like Jedi, love was a dangerous emotion to the Sith. Some Jedi discouraged love because it led to attachment. The Sith taught that love could be a beneficial emotion because it often lead to anger or hatred, which fueled a Sith's power in the Force. Often, however, love lead to mercy, which was one of the worst emotions a Sith could have, as it displayed weakness. The Sith did not believe in showing mercy to those weaker than you, as that meant beings that were unfit still survived. The only way to ensure the survival of the strong was for the strong to prove their power by removing obstacles that stood in their path, including, if necessary, those weaker than them. Contrary to popular belief, removal did not always mean death, though many Sith were ruthless and considered leaving potential opponents alive to be a weakness.
The Sith codeEdit
The Sith Code was the mantra that reinforced the core beliefs of the Sith Order.
- Peace is a lie, there is only passion.
- Through passion, I gain strength.
- Through strength, I gain power.
- Through power, I gain victory.
- Through victory, my chains are broken.
- The Force shall free me.
The history of the Sith starts almost twenty-five millennia before the destruction of the first Death Star at the Battle of Yavin. The Jedi Order formed during this time along with the creation of the Galactic Republic. Up until that point, the Force was practiced in varied and undisciplined ways. On many worlds the Force was misunderstood and often considered to be magic. Force adepts were either revered and worshipped, or shunned and feared.
The founding members of the Jedi Order were Force-sensitive individuals who understood the power and potential of the Force and also foresaw its abuse and danger. They agreed to pool their knowledge of the Force, continue to study it, and most importantly educate and regulate those who possessed the power. The Jedi Order was dedicated to making sure the Force was used to ensure peace in the galaxy.
Though the dark side of the Force was not well understood by the Jedi, they were aware of its presence. Early Jedi had all felt the lure of the dark side and agreed that the dark path was not one ever to be tread upon by a Jedi, not even for a moment.
However, not all of the early Jedi agreed.
A Long Time Ago…Edit
The debate about the value of the dark side of the Force waged on tirelessly in the Jedi Council. Dissident Jedi argued that the dark power could be controlled and used to further the Jedi cause, but the Council didn't agree. This debate eventually gave way to struggle, then war. This war came to be known as The Great Schism. For one hundred years, Jedi fought Jedi in the first conflict between the light and dark sides of the Force.
Because of greater numbers, the Jedi eventually prevailed and decimated the dark Jedi. The battered, surviving dark Jedi were captured and exiled. They were ordered to take the remnants of their broken fleet across the galaxy into uncharted space and never again darken the doorstep of the Republic.
As they traveled backwater space in exile, the outcast Jedi eventually came across the uncharted world of Korriban. There they found a primitive race of Force adepts known as the Sith. The native Sith knew nothing of the Force and used their untapped power for simple magic. The dark Jedi immediately saw an opportunity. They conquered and enslaved the Sith.
For the next several thousand years, the Sith worshipped the dark Jedi as gods. The rebel Jedi came to call themselves Sith Lords. These Sith Lords used the indigenous people as slave labor to build a great new civilization. Inter-breeding blurred species lines and eventually the term Sith came to mean the off-world, native and hybrid peoples of Korriban.
The Golden Age of the SithEdit
Now the dark side of the Force was studied and practiced with the same resources and diligence as the light side of the Force. The Sith grew in numbers and power, eventually spreading to the many systems near Korriban. The Sith Empire was born. The Sith Empire was led by one all-powerful dark master called The Dark Lord of the Sith. There was only one, and this title was usually won by defeating the previous Dark Lord of the Sith. The first Dark Lord of the Sith worth noting ruled 5,500 years before the Trade Federation of Naboo. He was Marka Ragnos.
Ragnos defeated the previous Dark Lord Simmus for the title and Ragnos' rule ushered in the pinnacle of the Golden Age of the Sith. Ragnos was in power for nearly two hundred years. He brought unparalleled prosperity, growth and order to the Sith Empire. Ragnos was never successfully challenged and eventually died of old age. At his funeral two Sith Lords named Naga Sadow and Ludo Kressh began to duel over who would next hold the title Dark Lord of the Sith.
Sadow believed that the Sith needed to expand the Empire, while Kressh believed that the Sith needed to avoid attracting the attention of the Jedi. Both Sith Lords knew of the Jedi and the Republic, but knowledge of the Sith's ancient enemy was not something shared by many other Sith. After remaining hidden for thousands of years, the Sith were unsure if the Republic and the Jedi still existed.
Then two hyperspace explorers from the Republic accidentally crashed on Korriban, unwittingly providing the Sith with the proof and information they needed to declare war.
The Great Hyperspace WarEdit
In the midst of a temporary truce, the two Dark Lord candidates Naga Sadow and Ludo Kressh convened to discuss the fate of Jori and Gav Deragon, the two hapless explorers who stumbled across the Sith Empire.
Kressh saw the intruders as a threat and wanted them executed immediately, while Sadow saw them as a path back to the Republic and eventual control of the Galaxy. Sadow eventually staged a rescue attempt on Korriban and blamed the Republic. Outraged, the Sith voted Sadow onto the throne of the Dark Lord and authorized Sadow's invasion of the Republic.
The Sith invaded and brutalized the Republic. The Jedi fought hard to defend the Republic, but in the end the leader of the Sith invasion force betrayed Sadow and turned the tide of the war. Sensing imminent defeat, Sadow used the force to detonate a nearby star, wiping out Jedi, Sith, Republic forces and billions of innocent bystanders.
Sadow was exiled by the Sith, then took the remainder of his broken fleet and created a new Sith Empire on the remote world of Yavin IV. He ruled here until his death one hundred years later. All that remains of Sadow's Empire are the ruins of the Massassi Temples.
The Freedon Nadd UprisingEdit
Over the next thousand years, the Sith on Korriban all but died out and Sadow's empire was a distant memory. An ambitious Sith Lord named Freedon Nadd was fed up with the decline of the Sith Empire and wanted to reform it with him as the new Dark Lord of the Sith. Unable to defeat the current Dark Lord, Nadd left Korriban and settled on the planet of Onderon. Nadd took over the ruling family of Onderon and ruled until his death. For generations afterwards, the power of the dark side was the driving force behind the government of Onderon.
When the Beast Wars erupted on the planet, the Jedi Council sent three Jedi to restore peace, including Ulic Qel-Droma. Though the Jedi successfully stopped the war there, their intervention fueled an uprising. The worshipers of Freedon Nadd revolted, but the Jedi quickly ended this bloody battle.
The Great Sith WarEdit
Four thousand years before the formation of the Galactic Empire, the Sith Empire was extinct. It was born again in the hands of a Jedi named Exar Kun. Fascinated by the dark side, Kun secretly studied the Sith during his Jedi training. His research led him to the moon of Onderon. From there he traveled to former Sith home world of Korriban and later to Yavin IV. Exar was led down the dark path by the ghost of Freedon Nadd who reavealed all of the Sith's dark secrets to the curious Jedi. Kun was eventually seduced by the dark side and swore his allegiance to the Sith.
At the same time, on the recently war-torn world of Onderon, a secret society of aristocrats called the Krath practiced the rituals of the Sith right under the noses of the Jedi.
The Jedi Ulic Qel-Droma discovered the Krath and set out to stop them. In retaliation, the Krath had Ulic's master killed by assassins. Ulic vowed to destroy the Krath from the inside, so he faced them and joined the dark organization. He was not strong enough to resist, however, and Ulic eventually slipped to the dark side. As a Jedi, Ulic was the Krath's greatest instrument.
Eventually the power of two Sith amulets -- one possessed by Exar and one by Ulic -- led the two Jedi to one another. The two dark Jedi were ready to kill each other when they were visited by a council of ghosts made up of past Dark Lords. The shades instructed them to work together to resurrect the Sith Order and restore the former glory of the Golden Age of the Sith. With Exar Kun as the Dark Lord of the Sith and Ulic Qel-Droma as his apprentice, the two Sith Lords waged the bloodiest war in Galactic history -- The Great Sith War.
Exar Kun returned to the Jedi Academy and began luring students to the dark side. Ulic took a small group of ships and used dark side trickery to begin capturing as many ships as he could. He was to build the next great Sith Fleet. In his travels Ulic came across the savage Mandalorian Warriors as they attacked a peaceful planet. Ulic intervened on behalf of the planet, but only so that he could arrange a one-on-one battle to the death with the Mandolorian leader. Ulic bested Mandalore in hand-to-hand combat and then took control of the Mandalorian hordes, adding them to his ever-growing battle force.
Exar and Ulic allowed the Republic to learn of their invasion and lured the Republic fleet away from Coruscant. The Sith forces then attacked the Capitol world. Ulic was captured by the Jedi, but was freed at his trial by Exar. Exar killed his former Jedi master that day and then compelled other Jedi students to do the same.
Later in the war, Ulic unleashed a powerful Sith weapon that caused a chain reaction and destroyed many stars. The fallout from this chain reaction vaporized many systems, destroying the Sith fleet and killing billions and billions of innocent people.
In the final days of the war on the planet Ossus, Ulic faced and killed his own brother. Horrified at what he had become, Ulic fell apart and was defeated by a Jedi who used a forbidden Force block spell that destroyed Ulic's ability to use the Force forever.
The Republic eventually tracked Exar to Yavin IV and began orbital bombardment of the planet. Surrounded by the mutated descendants of Sadow's followers, Exar used powerful Sith magic to drain these followers' life force and seal his own in the walls of the Massassi Temple. Exar Kun's body was destroyed but his evil spirit still remained.
The Jedi Civil WarEdit
Shortly after the Great Sith War, the remnants of the Mandalorians sensed weakness in the Republic and decided to strike. A long and bloody war followed between the Jedi and the Mandalorians, but in the end the Jedi prevailed. Two Jedi named Revan and Malak led a Republic fleet to the outer rim and successfully wiped out the Mandalorians. At the end of the war, Revan and Malak were revered as heroes.
Little did the Republic know that their Jedi heroes were destined to become two of the most brutal Sith Lords ever known. While in deep space, the two Jedi landed on Korriban and uncovered many secrets of the Sith. Corrupted by their newfound knowledge and the brutality of the war they had just won, the two Jedi renounced the Order, became Sith and changed their names to Darth Revan and Darth Malak -- master and apprentice.
The two Sith Lords had the loyalty of Jedi and Republic forces that they had led to destroy the Mandalorians. They took their new Sith fleet and waged a two-year war on the Republic's outer-rim territories.
Eventually, power hungry Darth Malak tried to destroy both his master Revan and the Jedi. His plan failed, but it did allow the Jedi to capture Revan alive.
The Jedi wiped the Sith master's memory, brainwashing and retraining Revan as a Jedi. In a most uncharacteristic move, the Jedi Council approved the use of Revan as a pawn to find the fugitive Sith Lord Darth Malak.
Eventually Revan tracked Malak to Star Forge and defeated him in a lightsaber duel. After that, Revan disappeared. The Sith were once again vanquished.
However...in a parallel universe Revan returned to the Dark Side of the Force, slayed Malak and with the help of Bastila Shan, a former Jedi, took over the Republic. Leaving the Galaxy in Darkness for the next four thousand years...
The New Sith WarEdit
Just as they had been born 25,000 years ago, the Sith were born again in the halls of the Jedi Council. This happened 1000 years before the Battle of Naboo.
It began when an unknown, lackluster Jedi began to discover the power of the dark side. He was shunned by the Council and forbidden to continue his study of the dark side. He eventually left the Order and was able to take other Jedi with him, convincing them that the council was holding them back. After a short while and a few more defections the new Sith Order had grown to fifty sworn Lords.
As time passed, the new Sith Order recruited an army of minions and declared war on the Jedi Order. The war was brutal but short and played out over several small battles. In the end, the Sith were responsible for their own defeat. The infighting, poor organization and endless power struggles destroyed the Sith Order from the inside.
The final battle of the New Sith War took place on the planet of Ruusan. The Jedi backed the Sith Lords into a cavern and were only minutes away from ending the war. In the final moments of the battle, the Sith Lord Darth Bane was arguing with another Sith Lord about the best way to turn the tide of the battle. He had a plan, but so did the others. Bane was betrayed in the heat of battle by a Sith Lord named Kaan and this resulted in the massacre on Ruusan. Kaan detonated a bomb that killed all the Jedi and all the Sith Lords save one, Darth Bane.
The Jedi felt they had finally wiped out the Sith. They were careful to guard all of their secrets and closely monitored students who showed dark side tendencies. After thousands of years of war and mistakes, the Jedi were determined to never again let the Sith rise.
Darth Bane, the sole surviving Sith Lord, slipped away into the shadows. Bane reformed the Sith doctrine and founded what is known as the modern era of the Sith. Now there are only two Sith at a time -- a master and an apprentice. They bide their time, work from the shadows, pass the Sith tradition down from master to apprentice and wait for the day they will have their revenge.
Darth Plagueis the Wise was a Sith Lord who lived during the thousand years of Sith 'extinction' between Darth Bane and the Battle of Naboo. He trained Darth Sidious in the ways of the Sith.
Plagueis furthered the teachings of Darth Bane, unlocking the deepest, darkest secrets of the Force. Darth Plagueis became a powerful Sith Lord during the thousand years leading up to the Battle of Naboo, and took on a Sith apprentice to whom he gave the name Darth Sidious. Sidious' early life remains shrouded in mystery, though he learned much from Plagueis, and grew even more powerful than his Master. Plagueis realized Sidious could well implement the final stages of the revenge of the Sith, and began to teach his apprentice his most important secrets. In his study of the dark arts, Darth Plagueis had somehow found a way to cheat death; to manipulate midi-chlorians to sustain and even create life through the Force. This secret he never taught to his pupil, forcing Sidious to assassinate him and attempt to discover the secret himself. Sidious would later remark on the irony of Plagueis' ability to save anyone from death but himself.
Sidious later told the 'tragedy' of Darth Plagueis to Anakin Skywalker, luring him to the dark side with the notion of eternal life. Skywalker, plagued by disturbing visions of the death of his wife, was soon corrupted. As Anakin swore alligience to him, Sidious declared that together they could rediscover Plagueis' lost secret.
It has been speculated that, given that Anakin was supposedly born of a virgin birth, it is possible that Darth Plagueis was the one who influenced the midi-chlorians that 'fathered' Anakin, thus making him a sort of father by extension. Further speculation produces the possibility that this may have spurred Sidious into killing his master, so that he may take Anakin as his own, potentially as a vital piece in discovering the Plaugeuis' secret.
The Clone WarsEdit
That revenge finally came almost two hundred years later, when a senator from the peaceful planet of Naboo rose to power as Chancellor of the Republic. Senator Palpatine orchestrated an invasion of his home world of Naboo, thus setting a series of deft political moves into motion. No one around him knew that Chancellor Palpatine was actually Darth Sidious, Dark Lord of the Sith. The Republic was now controlled by the Sith.
Sidious' first apprentice, Darth Maul, was killed in the invasion of Naboo by the Jedi Obi-Wan Kenobi. He later took a second apprentice, Darth Tyranus (a well-respected Jedi and political idealist named Count Dooku), whom he used to lead the orchestrated Separatist movement that threatened the Republic with war.
Darth Sidious used the threat of war to justify the creation of a huge clone army. The Clone Wars had begun.
The Jedi and clone army fought side by side, eventually defeating the Separatists. Darth Sidious blamed the Clone Wars on the corruption of the Republic and used the special emergency powers granted to him during the wars to re-organize the Galactic Republic as the first Galactic Empire and name himself Emperor.
The Jedi PurgeEdit
The Jedi Council was opposed to Emperor Palpatine (Darth Sidious). The Emperor named the Jedi enemies of the Republic and used one of the Clone Wars' greatest heroes, a Jedi named Anakin Skywalker, to lead the clone army against the Jedi. Anakin killed Darth Tyranus, went over to the dark side, and became Darth Vader, the most legendary of all Sith Lords.
Vader and his clone army began to hunt down and destroy all of the Jedi. Vader eventually faced his former Jedi master, Obi-Wan Kenobi, in a lightsaber battle. Kenobi defeated him and Vader was seriously wounded. He was restored by several operations that made him half man, half machine. Now in his new form, Darth Vader became the dark enforcer of the Emperor. With the Republic dissolved and the Empire formed, Sidious had secured the Sith as the rulers of the galaxy.
The Galactic Civil WarEdit
For twenty years the Empire ruled with an iron fist. The Jedi and the Force were long lost, but a tiny rebellion of politicians and soldiers formed to oppose the rule of the Emperor. The first great battle of the Galactic Civil War was the Battle of Yavin. Rebel pilot Luke Skywalker made a force-guided shot that destroyed the Empire's mighty battle station, the Death Star. Darth Vader managed to escape the battle with his life and kill his former master Obi-Wan Kenobi.
After the Battle of Yavin, Vader took the Imperial fleet and scoured the galaxy, searching for the rebel base and more importantly his son, Luke Skywalker. Both Vader and the Emperor felt that Skywalker was a great threat but could be a powerful ally if he could be turned into a Sith Lord. Luke Skywalker had actually been training with Jedi Master Yoda, who hid for years on the backwater planet of Dagobah.
After Vader and his forces crushed the Rebels in the Battle of Hoth, he continued to search for his son. They eventually faced each other in a lightsaber duel on Cloud City in the sky of Bespin. After severing Skywalker's right hand at the wrist, Vader pleaded with son to join him. Vader wanted to destroy the Emperor, end the Civil War and rule the Galaxy together with his son as his apprentice. Luke refused and escaped.
The Empire built a second Death Star and the Rebel Alliance set out to destroy it. Skywalker knew his destiny was to face his father. He believed that his role was not to destroy his father, but to turn him back to the light side of the Force. On the forest moon of Endor, Luke surrendered to Darth Vader and was taken before the Emperor.
The final battle of the Galactic Civil War was fought on many fronts. The Emperor lured the Rebels to the second Death Star and trapped their fleet between his own fleet and the functional, though incomplete, battle station. On Endor, a band of Rebels fought to knock out the shield generator that protected the second Death Star. In the Emperor's throne room, Jedi Knight Luke Skywalker fought for his destiny, as Darth Sidious tried to turn him to the dark side of the Force.
Luke eventually faced his father again in a lightsaber duel. After a moment of weakness revealed Luke's knowledge of his sister Leia to Vader, the Dark Lord promised to turn her to the dark side. Giving in to the dark side, Luke attacked his father and severed his mechanical right hand. Then he regained control and refused to fight. The Emperor, disgusted with Luke, began killing him with Force lightning.
Vader, realizing his life had been spared by his son, turned on his master and killed the Emperor. He died minutes later, after reconciling with his son.
The Rebels took down the shield generator and destroyed the Death Star. Both the war and the Empire were over.
The Sith Will Never DieEdit
After the Battle of Endor, the Sith continued to cause problems for the fledgling New Jedi Order established by Jedi master Luke Skywalker. Using the deepest and darkest of the Sith arts, the ghost of Emperor Palpatine (Darth Sidious) eventually found its way to a new clone body. In an attempt to stop the new Emperor, Luke traveled to face him on the dark world of Byss. This resurrected Sith Lord managed to turn Skywalker to the Dark Side, but he was later saved by his Jedi sister, Princess Leia Solo.
Later, the ghost of ancient Sith Lord Exar Kun was awakened from its sleep deep within the Temples of Yavin IV when Luke set out to establish a new Jedi Academy in the old ruins. Kun's spirit corrupted two of Luke's students and trapped the Jedi Master in a spirit realm before Luke and his students were able to destroy the specter. They did this by using the light side of the Force to fight Kun in both the corporeal and spirit realms.
It's clear that as long as there are Jedi in the galaxy, there will also be the potential for the Sith to rise again.