Indeed, at one point in the movie The Fellowship of the Ring, Saruman explicitly states of Sauron that 'he cannot yet take physical form' (though nothing comparable to this appears in the book).
So Sauron is not a man, nor has he ever been a man. Sauron is a Maiar, a lesser race of gods who could be considered Tolkien's version of Christianity's angels. The Maiar serve the higher gods, the Valar, who in turn work for the top god with a capital 'G' Eru Ilúvatar.
During his time on Númenor, Sauron had disguised himself in a handsome mortal form, but its sinking destroyed his body and permanently robbed him of the ability to shape-shift. His spirit fled back to Mordor, where he built a new body and regained his strength.
Thanks to the power of the One Ring, Sauron's spirit escaped the ruin of Númenor, but his power was diminished. After that, he could no longer hide his awful, demon-like appearance. When he created a new body for himself, he could only rely on the power and malice that was stored up in his One Ring.
The mystery actually adhered fairly closely to The Lord of the Rings author J.R.R. Tolkien's writings: In the mythology of Middle-earth, Sauron comes to the elves disguised as a “fair” man in order to trick them into forging the first three rings of power and learn their secrets in the process.
In The Lord of the Rings, it is said that had Galadriel chosen to use her powers for evil instead of good, she would have been even more destructive and terrifying than Sauron himself. Galadriel was the greatest and most powerful of all Elves in Middle Earth in the Third Age.
She already feels an outcast after Gil-galad tried to send her back to the Undying Lands, and she fears that if she reveals what she has done, it will be the final nail in the coffin. Instead, when Elrond pulls her from the river Glanduin, and she races back inside to Celebrimbor's forge, she chooses to stay silent.
Sauron, in disguise, deceived Celebrimbor and the smiths of Eregion into making Rings of Power, and then secretly made the One Ring to gain control over all the others, and so dominate Middle-earth.
It is therefore unlikely that Galadriel would have been able to save him or turn him towards the light if she had agreed to rule beside him. She even tells him this herself when she whispers: “No penance could erase the evil you have done.”
Sauron was the most powerful of the Maiar—primordial spirits created to help the Valar first shape the World. His original name was Mairon, which means "the Admirable," and as an immortal spirit born before the world's creation, he was able to perceive the Creator Eru Ilúvatar directly.
Enslaved peoples were those races that had fallen under the sway of the evil spirits Morgoth and Sauron, also known by the Free Peoples as 'Servants of the Enemy'. They included Orcs, Trolls and Men.
While the book version of Sauron is Pure Evil, due to being a manipulative sadist, which was shown in The Silmarillion, his lack of personality and motives in both the Ralph Bakshi and Rankin-Bass movies renders him as not even close to qualifying in those versions.
Legacyedit edit source. Thus Sauron's power was unmade, and his dominion in Middle-earth came to an end. According to Gandalf, Sauron was "maimed for ever, becoming a mere spirit of malice that gnaws itself in the shadows, but cannot again grow or take shape."
Sauron was hunting for the Ring so that he could again take physical form, and the Great Eye was a way to show his relentless search for the Ring. Peter Jackson chose to show Sauron as a fiery, lidless eye so that Sauron would feel more like the present and growing threat that he was.
The Eye of Sauron, generally called the Eye, was a symbol of Sauron the Dark Lord, mainly acknowledged when it was perceived by Frodo Baggins while carrying the One Ring. The Eye was projected as a mental image to show Sauron's unceasing vigilance and piercing perception.
So Season 1 of The Rings of Power works basically as an origin story for Sauron. Instead of just seeing the villain being bad just because of a predefined conception of who he was, we saw him actually trying to be good for once, then embracing his evil nature.
Sauron Feared Galadriel
Tolkien also stated that Sauron saw Galadriel as his equal, and therefore, in his rise to power he feared that she would go after that power herself. As we saw in The Fellowship of the Ring, Galadriel told Frodo that the One Ring would consume her and turn her into a Dark Queen.
Though Galadriel doesn't share her news, Elrond is suspicious and wanders out to find the genealogy scroll that leads him to figure out that Halbrand is Sauron. Unfortunately, he finds this news too late, arriving back at the workshop just as the elven rings (the rings of power) are being completed.
The Dark Lord easily overpowers her, and after Galadriel rejects his proposal to join him, he traps her in illusions and leaves her to drown in the water.
After he was attacked by the orcs, they transported his lifeless body to Mordor at Sauron's behest. Sauron revived Isildur with one of the nine rings, and then tortured him until his spirit was broken and he became a Nazgûl.
Although the finale, “Alloyed,” opens with the reveal that the Stranger is Sauron, that's a fakeout, and the trio of white-cloaked women who were after him was mistaken. We later learn that Halbrand is Sauron, while the Stranger is one of the Istari — the formal name for wizards in Middle-earth.
Gandalf, like all the five wizards of Middle-earth, was a Maia, an angelic spirit of the same order as Sauron.
In Lord of the Rings, Galadriel was not shown as a warrior, which makes the comparison with the character depicted in The Rings of Power jarring and difficult to reconcile. There's considerable contention surrounding the idea that she was a warrior with many battles under her belt.
Since they weren't actually wearing their rings anymore, Sauron had no ability to control them. Once he lost the One, his ability to command any of the Rings of Power was lost1; in fact, there's evidence to suggest that he was only able to control the Nazgûl because he had the Nine in his physical possession.
Tolkien suggested that Sauron did not discover where the Three were hidden, though he guessed that they were given to Gil-galad and Galadriel.