Anakin rescues Chancellor Palpatine: Obi-Wan Kenobi and Anakin Skywalker lead a mission to rescue Supreme Chancellor Palpatine from General Grievous and Sith Lord Count Dooku. At Palpatine's encouragement, Anakin kills Dooku. Palpatine then continues attempting to lure Anakin to the dark side.
The birth of Darth Vader: Anakin discovers that Palpatine is actually Darth Sidious. Mace Windu confronts him after Anakin reports his findings. Convinced that the Sith Lord has the key to saving his pregnant wife Padmé from his visions of her dying in childbirth, Anakin assists Palpatine. Anakin is officially on the dark side, and Palpatine dubs him Darth Vader.
Obi-Wan vs. Darth Vader: Under Palpatine's orders, Darth Vader slaughters everyone in the Jedi Temple, as well as the Separatist leaders on Mustafar. After Padmé fails to bring him back to the light side, Anakin Force chokes her into unconsciousness in his rage. In the hopes of stopping his power trip, Obi-Wan battles Anakin and leaves him badly disfigured and burned.
The rebirth of Darth Vader: Sidious rescues Vader using a stasis-pod. At a medical facility, he is given prosthetic and robotic replacement body parts. He also gets outfitted in his iconic black armor and face mask. Palatine tells him that he accidentally killed Padmé, effectively breaking him down entirely. Later, they oversee the construction of the Death Star.
Padmé gives birth: Though Padmé dies in the process, she gives birth to twins. For their safety, they are separated — Senator Bail Organa takes Leia to Alderaan, and Obi-Wan leaves Luke with Owen and Beru Lars on Tatooine.