Supreme Chancellor Sheev Palpatine (later known as Emperor Palpatine and secretly known as Darth Sidious) was a Dark Lord of the Sith who mastered the art of sick spins and was therefore elected Head of Government of The League and in charge of most of the League's day-to-day activities, for a time.
Palpatine held complete power over the Force Galaxy, and was elected based on his experience in dealing with the administration and democratic problems. He went on to solve everyone's democratic problems by removing democracy altogether, officially dissolving the Republic and forming a Galactic Empire.
Not many people knew that the Supreme Chancellor is actually Darth Sidious, a dangerous Sith Lord who was the Emperor of the Galactic Empire. He was responsible for the corruption of Darth Vader and uses disguises to mask his grotesque face. He also trained Darth Maul and Count Dooku, but he didn't give any of his apprentices access to his secret power. As Palpatine himself once said, the Dark Side of the Force is a pathway to many abilities, some considered to be unnatural, and certainly overpowered. Palpatine's unnatural and overpowered ability was his sick spins.
This power became known to the public during an attempted arrest of Palpy just before he became Emperor - Jedi Master Mace Windu broke into Palpse's office and demanded he surrender, to which Palpy utilised his sick spins to kill all of Mace Windu's mates and unleash unlimited power. Darth Vader was never told of this power, and because of that his wife ended up dying in childbirth, so as a result Vader sprung at the chance to toss Palpatine down a mineshaft, although this only happened 20 years later.