Sidious broke the Rule of Two at least twice: once by training Darth Maul while still under the tutelage of Darth Plagueis; and secondly, by taking on two apprentices at once, and in the form of two Jedi: Count Dooku, the former Padawan of the legendary Jedi Master Yoda, dubbed Darth Tyranus, and the Fosh Jedi Vergere.
Moreover, Palpatine outright broke the Sith Rule of Two following his resurrection after Return of the Jedi. Recuperating from Darth Vader's betrayal and plotting his grand comeback, Palpatine formed a massive Sith cult without ever training another true Sith Lord in the usual tradition.
The deaths of Sidious and Vader ended the Sith lineage that dated back to the creation of the Rule of Two. But while the Sith's destruction was foretold in the Jedi prophecy of the Chosen One, it did not mean the end of the dark side of the Force.
Dooku violated the Rule of Two himself and took on several apprentices throughout the Clone Wars. His first apprentice was Asajj Ventress, an assassin. While Ventress wasn't considered a true Sith as she lacked an official title, she yearned to be one and was trained by Dooku.
As we mentioned before, the Rule of Two involved only two Sith at any given time: a master and an apprentice. Because the Inquisitors are not true Sith, then the Rule of Two's criteria is not met. By training them, Darth Vader did not infringe on any rules.
The Sith remained hidden for a millennium, allowing the Jedi to believe that their ancient nemesis had gone extinct. The Sith stayed in hiding for a thousand years, their survival unknown to the Jedi, as they continued their revenge against the Jedi through Bane's Grand Plan.
A Sith Lord with the ability to prevent death and create life, Plagueis is the mentor of Sheev Palpatine/Darth Sidious, who, in accordance to the Sith's Rule of Two, eventually betrays Plagueis by murdering him in his sleep, taking his place as Sith Master.
The Rule of Three was a Nihil policy that involved the splitting of proceeds from the marauders' operations. The Eye of the Nihil—Asgar Ro, and later his son, Marchion—also received a share of the payouts from jobs that utilized the Paths that the Ros provided according to the Rule of Three.
After the Sith were decimated by the Jedi Knights of a thousand years ago, Bane enacted the Sith rule of two: there would be only two active Sith at one time -- a Dark Lord to embody the power, and an apprentice to crave it.
Sidious broke the Rule of Two at least twice: once by training Darth Maul while still under the tutelage of Darth Plagueis; and secondly, by taking on two apprentices at once, and in the form of two Jedi: Count Dooku, the former Padawan of the legendary Jedi Master Yoda, dubbed Darth Tyranus, and the Fosh Jedi Vergere.
In Darth Vader: Dark Lord of the Sith #7 by Charles Soule and Giuseppe Camuncoli, Emperor Palpatine admitted that the Jedi he most feared was not a skilled fighter or a Force prodigy, but a relatively weak Jedi.
Order 67 was an order requiring clone troopers to begin dancing. During the Battle of Utapau, Darth Sidious accidentally executed Order 67 when he meant to use Order 66. Just after the order was executed, Cody and his troops began dancing.
Darth Jar Jar, known to most as Jar Jar Binks, was a Gungan Sith Lord. He survived the Battle of Naboo and became a Representative of Naboo, when he helped to give Darth Sidious emergency powers.
In the Sith Empire, as time progressed pure-blooded Sith were steadily bred out, resulting in only a few pure-blooded Sith left in the Sith Empire by the time of the Great Hyperspace War (5000 BBY). By 44 ABY, the true Sith species in the Empire were believed to have gone extinct due to the interbreeding process.
Darth is often thought to be a combination of letters from the title Dark Lord of the Sith, a theory which is alluded to in Jedi vs. Sith: The Essential Guide to the Force. Darth may also be a portmanteau of dark and death.
Known survivors. It was said that fewer than one hundred Jedi—approximately one percent of the entire Order—survived Order 66.
Under the Rule of One, the followers of Krayt were taught blind obedience and absolute loyalty to the Dark Lord of the Sith, instead of the plotting and infighting of previous Sith organizations. Similarly to the Jedi Order, Sith Masters trained a single apprentice.
In the political arena, he reorganized the Republic into the Galactic Empire, installing himself as Emperor. Once more, the Sith ruled the galaxy, unbeknownst to all but the few surviving Jedi.
In non-canon material it is said that Palpatine had a number of concubines and never took a wife in fear that he would produce a legitimate heir. One of these non-canon concubines was Roganda Ismaren, a former Jedi who survived Order 66, and lived for a time at Palpatine's side.
Many throughout Sith history saw themselves, or were viewed, as this chosen one of legend: King Adas, Darth Andeddu, Darth Revan, Darth Malak, Darth Malgus, Darth Ruin, Darth Bane, Darth Tenebrous, Darth Plagueis, and Darth Sidious.
Qui-Gon Jinn was more attuned to the Force than any other prequel Jedi, and that's one reason why Emperor Palpatine needed him dead.
As the first Dark Lord of the Sith, Ajunta Pall founded the first Sith Empire and expanded it onto other worlds. The Sith took over the planet Ziost and created it as their capital and as Pall's new home.
Darth Sidious was able to cheat his upcoming death by transferring his spirit into a clone body while falling into the reactor core of the second Death Star. He later sought to prolong his existence by futilely manipulating his grandchild Rey into killing him so he could live further by possessing her body.
Sith masks were used during the days of the Jedi Civil War by some Sith to block outside influences and allow the user to focus without distraction. Many sith masks appeared to lack eye openings or otherwise restricted the vision, presumably requiring the wearer to perceive his or her surroundings through the Force.
Darth Sidious, publicly known as Sheev Palpatine from Naboo, became the Dark Lord of The Sith after betraying and murdering his Sith Master Darth Plagueis. Sidious was the Dark Lord of the Sith during the last years of the Republic and the rise of the Galactic Empire.