As a self-trained dark side user, Palpatine unsurprisingly would gain the attention of Darth Plagueis before the Jedi could discover him. As an aspiring Sith, Palpatine's presence would be hidden from the Jedi, both by Plagueis and Palpatine himself.
Well, the main reason they didn't know (and is something Yoda points out) is because the dark side clouds the minds of even the strongest light side users. And Palpatine was very good at masking his identity, seeing as he was incredibly strong with the force.
Description. Force clouding was a cloaking technique employed by the Sith to conceal their true nature from the Jedi and other users of the Force. The individual would pull their dark powers into themselves and adopt a mask of insignificance.
Well, first I will go over why he spared them. After Order 66, there were still a number of surviving Jedi. And while Palpatine knew that Vader was perfectly able to kill any remaining Jedi, there were too many for one man to kill alone. So, instead of killing all the Jedi he found, some were captured and tortured.
Qui-Gon is one of the most powerful Jedi in the saga: highly skilled in the Force and mastering abilities that other Jedi couldn't, including the ability to consciously manifest after death. But more than his abilities as an individual, it was his maverick philosophy that the Emperor feared.
Why Didn't the Jedi Find Palpatine When He Was Young?
Why did Yoda not sense Darth Sidious?
Sidious concealed his nature. Yoda sensed that the Dark Side was focused on the Jedi Order, but he didn't recognize Sidious until it was too late. The clearest demonstration of Sidious's skill is the fact that he dealt in person with Jedi Masters for 20 years and they never realized what he was.
As Palpatine's apprentice, Darth Vader was well aware of his Master's true identity; indeed, the revelation that Palpatine was Sidious was instrumental in Anakin Skywalker's fall to the dark side in Star Wars: Episode III - Revenge of the Sith.
Even as the hundreds of Jedi fought valiantly on Geonosis, they still didn't know. It wasn't until after Yoda, Obi-Wan, and Anakin had fought Dooku one-on-one that they found out he had been training as a Sith. As Yoda says, The dark side, I sense in you.
The young aristocrat was so adept at hiding his presence in the Force that even the experienced Dark Lord couldn't detect his power. Palpatine wished to join the Sith and his astounding aptitude for both the dark side of the Force and the ability to mask his true power resulted in the Jedi never discovering him.
This was probably why the Jedi did not notice Palpatine in the prequels either. Palpatine was able to control the Force inside himself at a young age and stay hidden. An explanation for this is that as a baby, the Force recognized the great potential and power that Palpatine had with it that it could hide Palpatine.
When Senator Palpatine succeeded Valorum as Chancellor, Amedda retained his position under the Republic's new leader. Amedda was one of the few in the galaxy who knew Palpatine was a Sith Lord, and assisted the Chancellor as Speaker of the Senate, helping him manipulate Senators into granting him more and more power.
The only thing Palpatine regrets is having to be “miraculously” revived for that abomination called The Rise of Skywalker. To be hanging around in a semi-comatose state only to get utterly destroyed again by one of his own progeny.
Very close. In the book Labyrinth of Evil, Mace Windu and his group of Jedi track darth sidious down to the 500 republica building. However, their trail stops cold there, and that's when the attack on coruscant is launched.
Just as Palpatine feigns to be helpless at Mace Windu's feet and claims a Jedi attempt on his life, Palpatine uses a form of Sith alchemy to disguise his true visage before the lightning breaks his illusory spell.
Even in the old Star Wars canon, the two had a confrontation, as they met in the comic book Star Wars Tales #9, where Maul pieced together that Anakin was Vader.
Did Emperor Palpatine know that Darth Vader was Anakin Skywalker before he revealed it to him? Yes, of course. Palpatine had known Anakin since childhood: “We shall watch your career with great interest”.
Dooku knew Palaptine was Darth Sidious, he tells as much to Obi-Wan in Episode II. Remember whe he's holding Kenobi as his prisoner? dooku tells Obi-Wan the Senate was being controlled by a Sith Master, remeber also the look Dooku shoots at Palpatine when he orders Anakin to kill Dooku.
Yes, he sensed Order 66 and Anakin's turn to the dark side. In fact, it's not hard for a Jedi Master like Yoda to do so. Ahsoka Tano even felt the disturbance in the Force when she actually heard Anakin's words right when he turned to the dark side. And mind you, this was when she was on route back to…
He believed that the Sith, who had used lightsabers for tradition since the time of Darth Bane, should have moved on from using lightsabers (which, though invented by a Sith, had become the symbol of the Jedi) and instead rely entirely on scheming and the Dark Side of the Force to earn and maintain their power.
Moreover, throughout the duel, Yoda continually adapts to and even matches Palpatine - forcing his enemy to constantly attempt new tactics. Palpatine clearly hated Master Yoda with a fierce passion, but he was under no illusions that the Grand Master would be easy to defeat.
Summary. Palpatine's true source of power comes from his intense hatred for everyone in the galaxy, which only fuels his strength. Not only that, but the more people hate Palpatine, the stronger he becomes as well, making inspiring hatred a crucial part of increasing his strength.
From the moment Palpatine began to plot his takeover, nothing he did was out of the goodness of his heart. Everything would transpire in a way that would give him power, and any niceties were a way to fool his enemies into underestimating him.
