Duel in Palpatine's office

With the Clone Wars reaching its end and the revelation that Supreme Chancellor Sheev Palpatine was secretly Darth Sidious, the Dark Lord of the Sith, Mace Windu and fellow members of the Jedi Council engaged Sidious in a lightsaber duel in the Chancellor's office on Coruscant. Sidious quickly murdered Jedi Masters Agen Kolar, and Saesee Tiin almost immediately, while Kit Fisto was murdered only a few seconds after, but Sidious had an extended confrontation with Windu. The lightsaber duel lasted until Windu disarmed the Sith Lord and knocked him to the floor.

As Windu held Sidious at bladepoint ready to kill him and end his madness once and for all, he was interrupted by the arrival of Jedi Knight Anakin Skywalker; although Windu had told Skywalker to remain at the Jedi Temple, he was seduced to the Chancellor's office by the promise that Palpatine could use the dark side of the Force to save his wife, Padmé Amidala, from dying in childbirth, an event Skywalker saw in a vision. Ignoring Skywalker, Windu declared Palpatine and the Sith as a whole defeated, to which Sidious responded by firing Force lightning at the Jedi Master. Windu managed to block the streams of electricity and deflected most it back into Sidious's body, disfiguring the Sith Lord in the process.

Skywalker attempted to convince Windu to arrest the Sith Lord, as he at first intended, but Windu had realized that Palpatine controlled the Senate and the judicial system, and would most likely be acquitted no matter what. Stating that Palpatine was just too dangerous to be left alive, Windu prepared to kill him, while Skywalker desperately claimed that doing so was not the Jedi way and finally blurting out "I need him!" When Windu tried to make the killing blow, Skywalker lashed out at him, severing his lightsaber-holding hand and allowing Sidious, who was feigning helplessness, to kill the Jedi Master.

In the aftermath of the duel, Skywalker pledged his loyalty to Sidious and became a Sith Lord called Darth Vader. The Jedi attempt on his life allowed Sidious to execute his plan to seize full control over the galaxy. He branded the Jedi as traitors and issued Order 66 to the Grand Army of the Republic, leading to the destruction of the Jedi Order. Shortly thereafter, he declared himself Galactic Emperor and transformed the Galactic Republic into the Galactic Empire, which ruled the galaxy for over two decades.

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