Darth Sidious was perhaps one of the most powerful, ruthless and successful Sith Lords the Jedi ever came across. Gaining his foothold in the Political arena by posing as both a Senator and later both as a Chancellor and an Emperor, Sidious, also known as Palpatine, was responsible for not only turning Anakin Skywalker to the dark side but also for nearly wiping out the entire Jedi population. His force powers and mind control were virtually unrivaled.