We do not and cannot know how long Morgoth was actively in rebellion to Eru and contending against the Valar, because before the creation of the Sun & Moon, there was no timekeeping in any sense that corresponds to our year. I’m in the camp that says the Spring of Arda lasted for hundreds of thousands of years, and also that the Elves were active for scores of millennia before the awakening of Men.
Anyway, to answer your question, I think that, at his worst, Sauron was a pale imitation of Melkor, and that Melkor’s reign of terror lasted longer and was far broader in extent. I also don’t think Sauron ever completely renounced his blasphemous worship of Melkor.
I googled this so don’t blame me if it’s wrong or give me any credit if it’s right but apparently Sauron has a small speaking role in the Silmarillion:
It was correct limit him in the book. That way when he posts of SDMB it is all the more terrifying. But his blog, “Sauron’s Blog”, kinda makes him look like Peter Pan’s Captain Hook.
He does make a few appearances in The Silmarillion and the various other books of notes. I find Sauron more evil than Morgoth, who comes off as a petulant spoiled child who started a really bad biker club to terrorize the civilians. Obviously, Morgoth was more powerful.
Bear in mind too that JRRT’s conceit is to present LOTR as an historical work, and history can only be based on sources that are extant. Everything that happens is something that witnesses by the Hobbit characters or by someone they would have been able to interview later (mainly Gimli and Legolas). That plus whatever later scholars would have been able to piece together after the “Red Book of Westmarch” was brought to Minas Tirith a generation or so later.
The paragraph describing Sauron’s reaction when he realized that the Ring had been brought to Mount Doom is something that an ancient scholar might get away with fabricating, brief as it is and based on some pretty good assumptions.
Notice too how little of Gandalf’s activities are related, except when the other characters are there to witness them or to hear his brief accounts of them later in the story. This goes along with Alka Selzer’s point about keeping other-than-human characters mysterious.
Sauron’s notable absence from the Lord of the Rings appears to be a somewhat common criticism of the book. Having your primary villain never appear in-the-flesh is certainly unconventional, but I think it works with the narrative. It’s never bothered me, personally. The only reason I think an appearance of Sauron would’ve added anything to the story is to provide a clearer explanation for his motives (power, dominion, and ultimately order). I don’t think that was ever discussed in the book itself beyond the most basic, as I recall having to turn to Tolkien’s Letters and HoME for that information.
As for my opinion on Sauron vs Morgoth: While Morgoth caused greater destruction and misery, Sauron was far more clever than his former master.
ISTR in one of his letters Tolkien said that Sauron was actually worshipped as a god by the orcs and his other evil minions, but I don’t think that really comes across in LOTR. Feared, yes, and certainly quickly obeyed when under his scrutiny or that of the Nazgul, but not really worshipped.
I once saw an interview with Sam Raimi of Evil Dead fame, he said something like “you can’t show the audience anything worse that they can imagine - so we show them, show them , show them”.
Basically meaning that he deliberately went over the top with his movies such that you imagined something really totally mega come the end.
And, if I’m not mistaken, the Evil Dead movies are viewed as much as comedy as thriller, aren’t they? As I said earlier, one person’s terror is another person’s belly-laugh.
Samwise: “Governor Sauron… I should have expected to find you holding Gollum’s leash. I recognized your foul stench…”
Sauron: “Charming to the last. You don’t know how hard I found it, signing the order to terminate your life.”
Samwise: “I’m surprised that you had the courage to take the responsibility yourself.”
General Glob: My Lord, the attack on Minas Tirith was a not successful.
Sauron: Unfortunate. ZAP. General Zop, congratulations on your promotion. I hope you produce better results.
Admiral Saruman: Don’t try to frighten us with your sorcerous ways, Lord Sauron. Your sad devotion to that ancient religion has not helped you conjure up the stolen ring, or given you enough clairvoyance to find those hobbits…
*
[Sauron raises a mailed hand in a pinching motion and Saruman starts choking] *
Sauron: ***I find your lack of faith… disturbing. ***
Sorry for the derail… You’re right of course, they do have “darkly” funny moments but the gore is amazingly over the top especially Evil Dead 1 (well it was in 1981 when it came out). I just said “of Evil Dead fame” to identify the director, I think he uses this technique in just about all his films eg. the over-the-top stunts in Spider Man for example to give you an extra high expectation of what the characters are capable of.
