Formed thousands of years prior to the Clone Wars, the Sith were ancient enemies of the Jedi Order. Established by a rogue Jedi, the Sith sought further knowledge and power through learning the Dark Side of the Force. Eventually, this Jedi was able to amass a sizable following, all of whom adhered to this new philosophy that embraced the dark side. This schism in the Jedi Order led to an event known as the Hundred-Year Darkness, in which the Jedi and the newly-founded Sith Order, once brothers and sisters in the Force, fought against one another for power. The civil war ended in the defeat of the Sith, who fled from known space. Unbeknownst to the Jedi however, the Sith settled on Moraband, a world of red sands, where they rebuilt in secret to wait for another chance to strike. As the Sith Order grew, they constructed massive temples and tombs Moraband in a location known as the Valley of the Dark Lords. The Sith established numerous Sith Empires through the use of slavery and fought wars against the Jedi for control of the galaxy.
Over the course of centuries, the Sith continued to expand their empire, constructing temples on planets such as Malachor, a world which would later become forbidden to the Jedi. At one point, nearly six thousand years before the rise of the Galactic Empire, the Sith built a shrine on Coruscant, which became a place of immense dark side power. Later in history, the Jedi raised their own temple over that shrine, in an attempt to contain and eliminate its power. Their quest to gain power was ultimately the undoing of the Sith, as the Dark Side made them turn against one another. Within a year, the Jedi managed to defeat the infighting Sith, bringing what was left of the dark order to its knees. Ultimately, after the Sith remained in hiding for a thousand years, their order would obtain galactic dominance by the end of the Clone Wars, after the reigning Dark Lord of the Sith Darth Sidious abolished the Republic and proclaimed himself the Galactic Emperor.
Original Sith Empire[]
The Sith Empire, later the Original Sith Empire, was a rich and powerful empire formed by the exiled rogue Jedi Ajunta Pall, who studied the forbidden arts of the Dark Side of the Force. Because of his defiance of the Jedi Council, he along with those who followed him were cast out in the wake of the Hundred-Year Darkness, from which the first Sith Order was born. After seizing control of the planet Moraband, the exiled Jedi began to interbred with the native species, beginning a long period of building and expansion. The Sith Empire developed in complete isolation for centuries before it was eventually rediscovered the Republic. Under the leadership of the Dark Lord of the Sith, Naga Sadow, the Empire briefly invaded Republic space, but was eventually defeated. The Sith Empire was believed to have been destroyed by the forces of the Republic during one of the many conflicts of Moraband. Despite their defeat, the Sith survived the conflict and ventured into the Unknown Regions to ensure the survival of their Order and the continued legacy of the Empire.
In this Empire the first to ever hold the title of Emperor was the Dark Lord Marka Ragnos, who would lead the Sith Empire into a Golden Age. Under the leadership of the Dark Lord Naga Sadow, the Empire invaded Republic space during a Great War, but was ultimately defeated.
Exiled Jedi[]
The term Exiles was used in the time of the Old Republic which referred to the Dark Jedi survivors of the Hundred-Year Darkness who were captured and banished into the Unknown Regions along with those who had served them. After they eventually reached Moraband, a planet strong in the Dark Side of the Force and home to the Sith people. They awed the primitive species with their display of dark power, and sought to overthrow their leadership. After which they declared themselves rulers of the Sith people and became known as the Lords of the Sith, with their leader being called the "Dark Lord" of the Sith. The Exiles used their alchemical arts to blend their DNA with those of the Sith, allowing their lineage to continue through the Sith species.
Sith Council[]
The Sith Council was a group of several Lords within the Sith Empire who served as advisers to the Dark Lord of the Sith. The Sith Council managed the affairs of the Empire, with each Lord that sat on the Council personally ruling over a minimum of a dozen worlds. Naga Sadow, Ludo Kressh, and Dor Gal-ram were three of the several Sith Lords on the Council under the Dark Lord of the Sith Marka Ragnos. After Ragnos died, the Lords on the council fought one another for the title of Dark Lord of the Sith, creating a rift within the council. Eventually, Naga Sadow was able to secure his hold over the title of Dark Lord after soundly defeating those who attempted to steal the throne away from him.
Resurgent Sith Empire[]
From the remnants of the Original Sith Empire came the Resurgent Sith Empire, created after the fall of the Original Empire at the hands of the Galactic Republic. The survivors of the conflict fled known space to escape persecution by the Republic and the Jedi Order. During the process of rebuilding their forces, the being history would identify as the Sith Emperor proclaimed himself to be the Dark Lord of his order and leader of his people. Under the care of this Emperor and his Dark Council of Sith Lords, the Empire established a capital and began building a mighty war machine, with the intent of eventually returning to combat with the Galactic Republic once more. The Empire worked towards that goal for centuries, gradually expanding and gaining more power and influence. The circumstances revolving around the collapse of this order haven't been clearly identified, but it is believed that around a few thousand years before the Battle of Yavin either the government was either a shadow of its former self or it was absorbed by the Galactic Republic, which was then the dominant superpower in the Galaxy.
Dark Council[]
The Dark Council was a council that served as the ruling body of the reconstituted Sith Empire throughout much of the government's history. Each member of the Council held the title of Dark Lord of the Sith and controlled one of the domains of politics within the Empire, making the Council the most powerful individuals in the Empire below the Sith Emperor himself. Seats on the Council were hotly contested among the Sith, with the tenures of some Councilors lasting only months while others lasted decades, and every single individual within the entire Empire ultimately answered to one member of the Council through the Imperial hierarchy of power bases. Since its inception at the Empire's founding, the Dark Council tried and failed to overthrow the Emperor twice and its members were purged as a result.
Empire of Darth Revan[]
Towards the end of the Mandalorian Wars, while the Republic's Jedi commander Revan was stationed at the ancient Sith world of Malachor, he fell under the influence of the Dark Side of the Force. From there, Revan and his disciples followed a trail that led them into the Unknown Regions with almost a third of the Republic fleet. They eventually discovered that the Sith Empire still lived, and in an attempt to eliminate their Emperor, Revan and Malak's minds were completely by the Dark Side. The Emperor named the two Dark Lords of the Sith and bestowing the Darth title on them. Revan was to prepare the major offensive against the Republic by the order of the Emperor. However, the Emperor underestimated the two former Jedi's resolve as Revan and Malak broke free of their conditioning almost immediately upon their departure and began to act of their own will.
Revan founded a new Sith Empire in direct opposition to the Emperor, intending to conquer the Republic and remake it into something that could withstand the Emperor's assault. Adapting the teachings of the ancient Sith to his own needs, he then took his friend Malak as his apprentice. A year after their depature and apparent disappearance, Revan and Malak returned at the head of a massive invasion fleet made up of Republic vessels, crewed by experienced ex-Republic veterans, and commanded by some of the finest officers that the Republic had produced. Calling themselves the dark organization known as the Sith, they declared a direct opposition on the Galactic Republic and its Jedi protectors. They nearly succeeded in their conquest of the Republic, but after Revan was redeemed and Malak was killed, the Empire splintered into factions before eventually dissolving.
Revanchists[]
The Revanchists, also known as the Jedi Crusaders, were a renegade faction of the Jedi Order who joined the Galactic Republic during the Mandalorian Wars. A movement founded by the Jedi Knight Revan, who wished to take a more proactive role against the invading Mandalorian Neo-Crusaders. Under Revan's leadership, these Jedi went against the Jedi Council's wishes and participated in scouting missions on the Outer Rim. Although the Jedi Council did not give the Revanchists their full support, they begrudgingly allowed the Revanchists to join the armies under the banner of the Galactic Republic. During the conflict, the Revanchists, under the leadership of Revan and his friend and fellow Jedi Knight Malak, led the Republic to victory in numerous battles. Though the Republic would win the war, most of the Revanchists who survived the final battle fell to the Dark Side of the Force over the course of the next year. These Jedi now called Sith Knights followed the now Dark Lords Revan and his apprentice Malak, under their new Sith Empire.