The average lifespan for a Sith, without any assistance from medical technology, is around 250 years. Taking into account that Force sensitive beings have extended lifespans, most Sith can reach up to 400 years.
Now, Darth Vitiate lived for around 1,500 years, which is by far the longest lifespan of any Sith Lord on this list. With a major appearance in Star Wars: The Old Republic, Darth Vitiate presented himself as one of the big bads in the Star Wars universe.
Yes a Sith Lord can, and already has. Darth Andeddu created the Dark Rituals to transfer his essence from body to body to ensure eternal life. He was ultimately killed by his followers but he lived hundreds of years before that murder.
The Emperor Vitiate was a Sith Lord who successfully gained near immortality by draining the life force of an entire planet, later attempting to drain all life in the galaxy, which would give him true immortality.
By 44 ABY, the true Sith species in the Empire were believed to have gone extinct due to the interbreeding process. Characteristics shown would be determined depending on how much Dark Jedi or Sith blood an individual possessed due to interbreeding.
Their reign ended when Vader sacrificed himself by destroying his master, rendering the Sith extinct through the deaths of the final Dark Lords.
As the first Dark Lord of the Sith, Ajunta Pall founded the first Sith Empire and expanded it onto other worlds.
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.
Some Jedi achieved immortality as Force spirits, their consciousness preserved in the Force. Every living being became one with the Force during the process of dying.
Plenty of films, books and comics emphasize light side users struggling with this temptation. But there were also Force users on the dark side who changed their ways as well. Many Sith throughout Star Wars canon and legends were redeemed and turned to the light.
The Sith also had healing powers in the EU, though usually those abilities came with a cost or only worked for brief periods. Sith Lords like Darth Vader and Darth Bane could channel anger or pain to temporarily heal themselves.
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.
Darth Shain, headmaster of the Korriban Temple, took notice and convened with the Dark Councilor and Dark Lord of the Sith Darth Shane McMahon, who decided to confer the title of Sith Lord to the young apprentice at the age of 11, making him the youngest Sith Lord in the history of the Sith.
There are dozens of canon Jedi in the Star Wars universe. Opposing them stand the canonical servants of the Dark Side of the Force: The Sith. While many Sith Lords in Star Wars are mentioned, only six are detailed in canon: Bane, Plagueis, Sidious, Maul, Tyranus, and Vader.
1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
But the record Sith-killer is actually Darth Bane himself. Darth Bane, founder of the Rule of Two, killed more Sith than any Jedi in the history of the Star Wars galaxy. Thousands of years ago, a schism among the Jedi Order led to the creation of a new faction - one devoted to the dark side of the Force.
Requesting that Githany secretly teach him Force techniques she learned from the masters, Bane also began private lightsaber combat instruction with Kas'im.
Triclops Palpatine (son) Kendalina (daughter-in-law) Ken Palpatine (grandson) Mara Jade Skywalker (surrogate granddaughter)
In the Star Wars universe, Darth Bane is a powerful Sith Lord who lived one thousand years before the events of the films and is known for being the originator of the Sith's "Rule of Two", which states: "One master and one apprentice can be the only Sith in the galaxy at a time".
The term "Sith Lord" generally encompassed members of both sexes, although some female Sith such as Lumiya, Tahiri Veila, Olaris Rhea, and Vestara Khai were styled Sith Lady. Originally, "Sith Lord" referred to a high-ranking member of the Sith Order's society.
Formed many millennia prior to the Clone Wars, Sith were once part of the Jedi Order, a group of beings who wielded the Force and were dedicated to peace through using the Light Side of the Force.
Tulak Hord. An emperor of the early Sith Empire, Tulak Hord was an unrivaled force wielder and dualist. Known by many as the 'Lord of Hate' and 'Master of the Gathering Darkness'.
18 Galen Marek
Galen Marek is the only one who came close to destroying the Sith Lord, thanks to his vast knowledge of Vader's fighting tactics through the many hours they trained together.