While much of Emperor Palpatine’s EU backstory has been left in Legends, a tie-in book has brought one aspect of it back into Star Wars canon. The man who would eventually become the Emperor of the Star Wars galaxy was both a cunning political player and one of the galaxy’s most formidable Sith Lords as Sheev Palpatine and Darth Sidious. Palpatine excelled at both roles over the years, allowing the Sith to resurface and overthrow both the Republic and the Jedi, although his ambitions began long before the Star Wars prequels.
Plagueis
Palpatine trained under Darth Plagueis before Star Wars: Episode I – The Phantom Menace, the instructor he would later tell Anakin Skywalker about in Star Wars: Episode III – Revenge of the Sith. Plagueis is the topic of one of the most fascinating scenes in the entire Star Wars franchise, yet he never appeared on screen and much of his backstory has remained a mystery, at least in terms of canon materials. Thankfully, this is about to change, and with it, more information about Emperor Palpatine.
Darth Plagueis – Plagueis’ backstory and Palpatine’s Elevation
The 2012 novel Darth Plagueis, by James Luceno, is a fantastic source of a lot of that history and their relationship in terms of both Plagueis’ origin and Palpatine’s elevation through the ranks of the Sith and the Senate. When Disney rebranded the old EU as Legends, the book was declared non-canon, but as with many other things, certain elements have found their way back in. Secrets of the Sith, a canon Star Wars book written as though from Emperor Palpatine’s point of view in the Star Wars world, mentions his ascendancy, and it does accord with Legends in part:
“After centuries in the shadows, the Sith were poised to emerge once more. As a dark apprentice, I sensed that the Galactic Republic was in disarray. Its delegates held no interest in the common good. They would be easy targets for my influence. Serving as a senator, I manipulated their greed in my favor. With each new act of legislation, I rose through their ranks. Total control of the galaxy’s governing body drew ever closer. But ascension in the Senate would not be enough. My master, Darth Plagueis, had served his purpose. I struck him down, claiming his place as the one true master of the Sith.”
Palpatine’s technique of ascending through the ranks is quite similar to that described in the Darth Plagueis Legends book, in which he was brought under the Sith Lord’s tutelage and began to work his way up the political ladder, influencing those he needed to and killing those he couldn’t. This involves assassinating Naboo’s Senator so that he might assume his place and advance farther in the galaxy, aligning with his and Plagueis’ ambitions of restoring the Sith to greatness while also acquiring ruler authority. This ascent took place over several decades in the novel, and it appears to be the same in canon.