"The Necromancer"

[Legolas]

All good points here, and I do love what you pointed out. With the load of material we're given about this world, there's still much left to wonder about, and it's always a joy to come across people who are just discovering it for the first time.

It lies outside of the story, but it is worth remembering (or pointing out) the writing process. Among others (some with names and places with roots in Tolkien's Quenta Silmarillion),"The Necromancer" was originally just some 'black sorcerer' that Tolkien alluded to in The Hobbit as a device to make the world seem much more vast and dangerous than little ole Bilbo and his hobbit hole. He was simply namedropping. At time of publishing, Tolkien didn't know the Necromancer would be revealed as Sauron or what Sauron would be doing in Bilbo's world. It was a self-contained child's tale written with no intention of a sequel.

Even the most integral parts of the story behind The Lord Of The Rings including the story behind the Ring's power and the full identity/activities of the Necromancer and Gandalf were not conceived until after The Hobbit was published. So many people wrote Tolkien to ask for more details that he decided to write the sequel. How did the Ring come about? Where does Gandalf go? What's the Necromancer doing?

Responding to his publisher's letters in late 1937 onward encouraging him to write a follow-up to The Hobbit, he wrote:

But if it is true that The Hobbit has come to stay and more will be wanted, I will start the process of thought, and try to get some idea of a theme drawn from this material for treatment in a similar style and for a similar audience – possibly including actual hobbits. My daughter would like something on the Took family. One reader wants fuller details about Gandalf and the Necromancer. But that is too dark – much too much for Richard Hughes' snag. I am afraid that snag appears in everything; though actually the presence (even if only on the borders) of the terrible is, I believe, what gives this imagined world its verisimilitude. A safe fairy-land is untrue to all worlds. (Letter 17)

I did not think any of the stuff [ed. - early draft of The Silmarillion] I dropped on you filled the bill. But I did want to know whether any of the stuff had any exterior non-personal value. I think it is plain that quite apart from it, a
sequel or successor to The Hobbit is called for. I promise to give this thought and attention. But I am sure you will sympathize when I say that the construction of elaborate and consistent mythology (and two languages) rather occupies the mind, and the Silmarils are in my heart. So that goodness knows what will happen. Mr Baggins began as a comic tale among conventional and inconsistent Grimm's fairy-tale dwarves, and got drawn into the edge of it – so that even Sauron the terrible peeped over the edge. (Letter 19)

The Hobbit sequel is still where it was, and I have only the vaguest notions of how to proceed. Not ever intending any sequel, I fear I squandered all my favourite 'motifs' and characters on the original 'Hobbit'. (Letter 23)

And later, updating them on the sequel's progress:

I think The Lord of the Rings is in itself a good deal better than The Hobbit, but it may not prove a very fit sequel. It is more grown up - but the audience for which The Hobbit was written has done that also. The readers young and old who clamoured for 'more about the 'Necromancer' are to blame, for the N. is not child's play. (Letter 35)

As The Lord Of the Rings was being written to answer these questions somewhat, it became darker and more adult, and the world of The Hobbit was fused into the previously separate world of Tolkien's legends (which he wasn't sure would ever be published). Because of this, small changes had to be made in The Hobbit in order to reconcile the two stories (particularly Chapter 5, the account of Bilbo winning the riddle game with Gollum, which is explained in a note at the front of subsequent editions).

Sauron's character as an evil apprentice of Morgoth evolved over the years of writing; he had several names and his nature shifted a few times (originally with feline connections) before Tolkien settled on "Sauron." At one time in the writing process Sauron was named Thû the Necromancer (in The Lay of Leithian, a story that takes thousands of years before The Hobbit) which is how the association came about (as evident above in the Letter 19 excerpt).

What Sauron was doing to be called that while in Dol Guldur thousands of years later is still anyone's guess, but as I said, it is mostly a consequence of Tolkien having not actually fleshed those details out at time of writing - the references to The Necromancer, Radagast, Gandalf's travels, a council of white wizards, and a number of other things were there to impress upon children that Bilbo lived in massive world where all sorts of other things bigger than he were moving and clashing with no intention of ever explaining them further.

This is a theme of the book for me, and Gandalf even closes the book with such a thought:

“You don’t really suppose, do you, that all your adventures and escapes were managed by mere luck, just for your sole benefit? You are a very fine person, Mr. Baggins, and I am very fond of you; but you are only quite a little fellow in a wide world after all!”

“Thank goodness!” said Bilbo laughing, and handed him the tobacco-jar.