Em resposta à sua pergunta, os Sith costumavam governar a galáxia antes que a República (e a Ordem Jedi) os derrubasse. Este ato é o que os Sith estão se vingando em Star Wars: Revenge of the Sith
“The Republic has fallen, Padmé,” Obi-Wan said gravely. “The Jedi Order is no more.” “I know.” Padmé gazed at him, seeing the new lines in his face. “It’s hard to believe.” She took a deep breath. “But the Senate is still intact. There is some hope.”
“No, Padmé,” Obi-Wan said sadly. “It’s over. The Sith now rule the galaxy, as they did before the Republic.”
Padmé stared. “The Sith?” It was Palpatine who was in charge of the Repub — of the Empire. Surely Obi-Wan didn’t mean that Palpatine was a Sith Lord!
As guerras clônicas e a Ordem 66 são a "vingança dos Sith"
[The] Clone Wars have always been, in and of themselves, from their very inception, the revenge of the Sith.
They were irresistible bait. They took place in remote locations, on planets that belonged, primarily, to “somebody else.” They were fought by expendable proxies. And they were constructed as a win-win situation.
The Clone Wars were the perfect Jedi trap.
e
A small hologram of the first of the clone commanders sprang up before him. “Yes, my lord?”
“The time has come,” Darth Sidious said, savoring the words. After a thousand years, the time for revenge has come at last. “Execute Order Sixty-six.”
Mace Windu nos dá essa visão. Como você pode ver, a queda de Darth Bane (e por extensão todos quase todos os Sith) foi claramente um ponto de virada nas relações Jedi / Sith:
“Since the fall of Darth Bane more than a millennium ago, there have been hundreds of thousands of Jedi-hundreds of thousands of Jedi feeding the light with each work of their hands, with each breath, with every beat of their hearts, bringing justice, building civil society, radiating peace, acting out of selfless love for all living things-and in all these thousand years, there have been only two Sith at any time.
Para apoiar isso, você tem citações de Palpatine que os Sith usavam para governar a galáxia;
e Windu afirmando que os Sith costumavam oprimir as pessoas