Sith

"Fear. Fear attracts the fearful. The strong. The weak. The innocent. The corrupt. Fear. Fear is my ally."

- Darth Maul

"Always two, there are; no more, no less. A master and an apprentice."

- Jedi Master Yoda

The Sith (officially known as The Brotherhood of Darkness, The Sith Empire, The Sith Triumvirate, and The Order of the Sith Lords - depending on the specific era of usage) are a dark order of Force sensitives in the Star Wars universe. Unlike the Jedi, who serve the light side of the Force and use positive emotions to further their dedication to peace, the Sith use the dark side of the Force to serve their power-hungry aims and desire to dominate others. Sith Lords usually possess red-bladed lightsabers, as opposed to the Jedi who, while avoiding the red colors, often use a variety of different colored lightsaber blades.

History of the first Sith and Dark Lords
The Sith's first ever Dark Lords and Sith Emperors who ruled the Galaxy were Marka Ragnos, Tulak Hord, Naga Sadow, Xendor, Ajunta Pall, and Ludo Kressh, the most powerful Sith Lords in the time of the Golden Age of the Sith, a period which came to an end when Ragnos died, leaving Sadow and Ludo to become each others' arch-rivals to occupy Ragnos' throne. Following the rise of the spirit of Ragnos and the deaths of Simus and Ludo, Sadow became the new ruler of the Sith Empire, but lost the Great Hyperspace war that he waged against the Jedi after being betrayed by Gav Daragon. Killed by his new apprentice while in exile, Sadow was buried in his tomb in the Sith Temples on Yavin IV. Freedon Nadd became the new Dark Lord and took over Onderon. After losing Onderon after his death, Nadd's descendants went through the same events and were killed too: King Ommin, Queen Amanora, Aleema Keto, and Satal Keto.

The Great Sith War
Centuries after his death, Nadd's tomb was explored by the Dark Jedi Exar Kun, who became Nadd's Sith Apprentice and passed tests under the guidance of Nadd's spirit. Kun destroyed Nadd's spirit and built up his own Sith Empire on Yavin IV, recruiting Mandalorians, the remnants of Sadow's demonic creation: the Massassi species, and the Krath Cult of the Empress Teta system. Kun took another fallen Jedi named Ulic Qel-Droma as his apprentice and both were christened Dark Lords by the spirit of Ragnos. Kun and Ulic then waged the Great Sith War against the Republic and the Jedi but Qel-Droma betrayed Kun and Kun and his Sith Empire were destroyed. The war weakened the Republic, but Kun's spirit still remains in the ruins of Yavin IV to this day...

The Mandalorian Wars and the fall of Revan and Malak
The true Sith Empire, however, remained elsewhere in the Galaxy on Dromund Kass were their new Sith Emperor became Dark Lord and was marked Dark Lord and Darth Vitiate by the spirit of Marka Ragnos. The Sith Empire was the true mind behind the Mandalorian Wars; the bloodiest war in Galactic History. The Mandalorians devastated the galaxy, but two Jedi Knights, Revan and Malak, destroyed the Mandalorians on Malachor V and slew their Mandalore leader. After destroying Malachor V, Revan and Malak found the Sith Empire and were corrupted by the Sith Emperor. Building up their own Sith Empires, Revan and Malak waged the Jedi Civil War against the Republic.

The Jedi Civil War
The Republic was nearly destroyed and only 100 Jedi were left and survived the war, but Revan was redeemed after Malak usurped his place as Dark Lord. After Revan joined the Jedi and saved the Republic, killed Malak and destroyed his and Malak's Sith Empire. The Star Forge was destroyed and the Jedi Civil War was ended in the Jedi's favour, but many worlds were left bombed and devastated by the Sith like Dantooine and Telos IV.

The Dark Wars and the First Jedi Purge
After the death of Malak and the disappearance of Revan, the Sith were left with no leader. But it turns out that Malachor V had survived its destruction and the Trayus Sith Academy rebuilt and gathered up all of the surviving Sith from the Jedi Civil War and they embraced the new Dark Lord, Darth Nihilus, as their new ruler of the Sith Empire and of the Sith Triumvirate after Lord Nihilus and Darth Sion exiled Darth Traya from the Sith. They then waged a ruthless, brutal and devastating war against the Jedi and the Republic. The Republic was devastated and destabilized, and then came the First Jedi Purge. Nihilus began destroying entire planets like Katarr, in the process he also killed notable High Jedi Masters including Master Lestin, Master Dorak and Master Vandar. The other Jedi were killed by Sion and his Sith Assassins until only 5 members of the Jedi Council were left, they scattered into hiding; Master Vrook went to Dantooine, Master Vash went to Korriban, Master Ell went to Nar Shaddaa, Master Atris went to Telos IV and Master Kavar went to Onderon. These Jedi Masters knew of the actions of the Sith, but were powerless to stop it. There was one other remaining Jedi who survived the war: the Jedi Exile Meetra Surik. Surik had been banished for defying the council with Revan and Malak and following Revan to war 10 years ago from then. Surik however found Traya (who had now taken the identity as her true name, Kreia) and travelled with her across the Galaxy to help the Jedi and gather them to deal with the Sith. As Surik travelled across the Galaxy, she fought her way through the Sith and their new allies, like the Onderon Separatists, killed Darth Sion and gathered Kavar, Vrook and Ell. But Kreia revealed herself as Darth Traya and killed the 3 masters. She then travelled to Telos IV and completed Atris' fall to the Dark Side. Surik duelled, defeated and then redeemed Atris, broke her bond with Kreia and destroyed the Sith Triumvirate. She then travelled to Malachor V, killed Sion and Traya, reclaimed her place as a Jedi and once again Malachor V was destroyed and this time forever.

Rule of Two
Throughout the rest of galactic history the Sith have existed in numerous incarnations. Sith armies battled the Jedi and the Republic until 1000 BBY; by this time all of the Sith had betrayed and killed each other off in a bloody civil war. Darth Bane was the only survivor and decided to adapt the system of having only two Sith in existence at a time, in order to prevent their ultimate extinction and preserve the dark teachings, creating the Rule of Two. Darth Plagueis carried out this tradition and took Palpatine as his apprentice, who would later kill Plagueis and usurp him.

Rule of One
The rule of two was later abolished after the final death of Darth Sidious and also abolished by Darth Krayt who had many Sith serving him when he created the Rule of One (in which there would be multiple Darths serving one Dark Lord of the Sith). Even after Lord Krayt's ultimate death, the One Sith still lived on as his apprentice, Darth Nihl, took Krayt's place, gathered up all of the remnants of Krayt's empire and they continued with their fight between the Jedi and the Republic, to avenge Krayt.