Sauron, the Necromancer

[William Cloud Hicklin]

That old thread likked above, from 2004, includes the sotrt of thing that can plague us all when new information is discovered:

Sauron existed in the mythology before the writing of The Hobbit. Originally called Thû, he entered Tolkien's writings during the 1920s as Morgoth's most powerful servant. However, when The Hobbit was published, the Necromancer was not intended to be Sauron: it was only when he came to write The Lord of the Rings that Tolkien realised how conveniently the two characters could be combined.

Ah, but John Rateliff's History of the Hobbit has rather changed things- from the very first draft of 'An Unexpected Party:'

[Gandalf (> Thorin, confusingly):] "We must give a thought to the Necromancer."
"Don't be absurd" said the wizard. "That is a job quite beyond the powers of all the dwarves, if they could be all gathered together again from the four corners of the world. And anyway his castle stands no more and he is flown to another darker place - Beren and Tinuviel broke his power, but that is quite another story."

So there you have it: "Sauron the terrible" was already "peeping over the edge" from the outset!