"Did you ever hear the tragedy of Darth Plagueis the Wise? It's not a story the Jedi would tell you. It's a Sith legend. Darth Plagueis was a Dark Lord of the Sith, so powerful and so wise, he could use the Force to influence the midi-chlorians to create… life. He had such a knowledge of the dark side, he could even keep the ones he cared about… from dying."

―Palpatine to Anakin Skywalker [src]

Darth Plagueis, the reigning Sith Lord, dies somehow (possibly killed by Palpatine AKA Darth Sidious) himself. This leaves Sidious as the reigning Dark Lord of the Sith. By this time, Plagueis had begun experimentation that would lead to the birth of a child through the midichlorians (Anakin Skywalker, who will be born to Shmi Skywalker next year). However, it is unclear as to whether Palpatine carries on Plagueis work to create Anakin or if Plaguis himself has already lead to the impregnation of Shmi. In either case, Palpatine/Sidious takes over watching for the birth of Anakin, and he brings his secret apprentice, Maul, from the shadows, now that he need not hide his secret training from Plagueis. (conjecture based on The New Essential Chronology) Quelle: Timeline Gold (PDF FIle)

Palpatine later related the so-called "Tragedy of Darth Plagueis the Wise" to Anakin Skywalker, luring him to the dark side with the possibility that he could learn Plagueis's secret of saving beings from death. Skywalker, plagued by disturbing visions of the death of his wife, was soon corrupted. As Skywalker swore allegiance to him, Sidious declared that together they could rediscover Plagueis's lost secret.

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