An ancient and legendary Sith Lord, it was Darth Bane who saw that the Sith traditions of old were ultimately a dead end. All too often, squabbling Sith in their bid for power upended carefully laid plans. 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. These Sith would operate in the shadows, favoring guile and conspiracy to bring down their opponents rather than brute force -- that is, until it was time to rise and subjugate the galaxy.
Darth Bane was a human male Dark Lord of the Sith and the sole survivor of the destruction of the Sith at the hands of the Jedi Order a thousand years before the Clone Wars. As the only surviving Sith, Bane recognized that Sith infighting had weakened them to the point that the Jedi could destroy them. To rectify this, Bane reformed the Sith and created the Rule of Two, mandating that there could be only two Sith—a Master and an apprentice—at any given time. These new Sith would begin a plot to destroy the Jedi in secret. Bane was later defeated by the Jedi, who wrongly believed that the Sith were defeated with him.
The vendetta Bane held against the Jedi was fulfilled during the Clone Wars, when the Sith Lord Darth Sidious, secretly Supreme Chancellor Palpatine and a follower of the Rule of Two, transformed the Galactic Republic into the Galactic Empire and destroyed the Jedi Order. The victory was short-lived, however, as the redeemed Jedi Knight Anakin Skywalker defeated the Sith twenty-three years later.