Emperor Palpatine being resurrected in Palpatine was the one who succeeded. After the events of Return of the Jedi, his spirit leaped into a clone body, and he hid himself away on a planet strong in the dark side while he developed a fleet of superweapons with which to retake the galaxy.
Most Star Wars fans will recognize that as a summary of Star Wars: The Rise of Skywalker. However, fans who are familiar with Star Wars' classic Expanded Universe will likely also realize it's an effective summary of Dark Empire, a miniseries by Tom Veitch and Cam Kennedy published in the early '90s. The story was very different - it saw Luke Skywalker fall to the dark side, for example - but the basic premise was the same. This was one of the most important stories in the old Star Wars Expanded Universe, but it was branded non-canon (or "Legends") after Disney acquired Lucasfilm in 2012.
Dark Empire was often mocked for the idea of bringing back the Emperor, but surprisingly the idea originated with George Lucas himself. As Veitch explained in an interview with clone body for the Emperor seemed like an easy solution, and Lucas gave it his seal of approval.
Palpatine's Clone Body Was Approve by George Lucas
Lucas may have been the one to come up with the idea of a resurrected Palpatine, but he clearly had no interest in using the idea himself. It never figured in any of his plans for the sequel trilogy (indeed - had it done so, he'd probably have refused to give consent). He was, however, delighted with the comic book miniseries; he famously even gave copies of the comic out as Christmas presents. It's no exaggeration to say that Dark Empire had Lucas' blessing.
Lucas may have approved of the idea of bringing Palpatine back, but he's stated many times that he's in favor of Star Wars always changing and evolving, suggesting that it was a story he wouldn't have been interested in telling. Nevertheless, while fans have called out the sequel trilogy for falling back on the villain when many had assumed Palpatine was gone for good, Dark Empire shows that not only did the idea already exist, but that George Lucas gave it his approval to enter Star Wars' official lore.
Source: Star Wars Underworld
