V. E. Humans
- What brought on the sinking of Numenor?
The Numenor story was Tolkien's re-telling of the Atlantis legend (the tale published in The Silmarillion was entitled "The Akallabeth", which may be translated as "Downfallen"). Numenor was an island far to the West, a "land apart" given to the heroic Edain (humans) of the First Age who had aided the Noldor in the wars against Morgoth (see LFAQ, General, 1). [The Line of Kings of Numenor was descended from Elrond's brother Elros, who chose to be mortal; it led indirectly to Elendil the Tall, first King of Arnor and Gondor, and thus eventually to Aragorn son of Arathorn.]
The theological situation was the "standard" one of a Ban and a Fall. The Numenoreans, despite having been granted a longer lifespan than other, humans, nevertheless had to remain mortal. They had also been ordered not to sail West to the Undying Lands (Valinor). After awhile (perhaps inevitably, as their power and wealth grew) the Numenoreans began to envy the Elves and to yearn for immortality themselves (so as to enjoy their situation longer). They managed to convince themselves that physical control of the Undying Lands would somehow produce this result (it would not have); however, they also retained sufficient wisdom not to attempt any such foolish action. Significantly, the more obsessed they became with death the more quickly it came as their lifespans steadily waned.
Near the end of the Second Age King Ar-Pharazon the Golden pridefully challenged Sauron for the mastery of Middle-earth. The Numenoreans won the confrontation (see LFAQ, Humans, 2) and took Sauron to Numenor as a prisoner. Still wielding the One Ring, he swiftly gained control over most of the Numenoreans (except for the Faithful and their leaders, Amandil and his son Elendil). As King Ar-Pharazon's death approached ("he felt the waning of his days and was besotted by fear of death"; RK, p. 317) Sauron finally convinced him by deception to attack Valinor. This was a mistake. A great chasm opened in the Sea and Numenor toppled into the abyss. (Tolkien had a recurrent dream about this event; in LotR he gave it to Faramir, who described it in "The Steward and the King".) (See also LFAQ, General, 2).
- How could Ar-Pharazon of Numenor defeat Sauron while Sauron wielded the One Ring?
He did not actually defeat Sauron himself. The invasion fleet of the Numenoreans was so powerful that Sauron's armies deserted him. Sauron merely pretended to humble himself; to be carried back to Numenor as a supposed hostage was exactly what he wanted. His plan was to weaken Numenor as a war power by maneuvering them into sending a fleet to attack Valinor, where it would presumably be destroyed.
He succeeded up to a point, but the result was disastrously more violent than he foresaw, and he was caught in the Fall of Numenor. Only his physical body perished since by nature he was of the spiritual order. Tolkien: "That Sauron was not himself destroyed in the anger of the One is not my fault: the problem of evil, and its apparent toleration, is a permanent one for all who concern themselves with our world. The indestructibility of spirits with free wills, even by the Creator of them, is also an inevitable feature, if one either believes in their existence, or feigns it in a story." (Letters, p. 280).
- What happened to the Ring when Numenor was destroyed?
Nothing. Sauron carried it back to Middle-earth, though there might be some question as to how he managed it. Tolkien said he did, and Tolkien should know: "Though reduced to 'a spirit of hatred borne on a dark wind', I do not think one need boggle at this spirit carrying off the One Ring, upon which his power of dominating minds now largely depended." (Letters, p. 280). In fact, as far as we know all the spiritual beings (Valar and Maiar) were perfectly capable of manipulating physical objects.
- Where did the Southrons come from? Were they part of the Atani?
Yes. All humans, East, West, North, or South, were. Humans first appeared in the east and spread westwards, with some eventually crossing the Blue Mountains into Beleriand. The entry for Atani in the Silmarillion index reads:
Atani 'The Second People', Men (singular Atan). Since in Beleriand for a long time the only Men known to the Noldor and Sindar were those of the Three Houses of the Elf-friends, this name (in the Sindarin form Adan, plural Edain) became specially associated with them, so that it was seldom applied to other Men who came later to Beleriand, or who were reported to be dwelling beyond the Mountains. But in the speech of Iluvatar the meaning is 'Men (in general)'.
[Humans were 'the second people' because Elves were the Firstborn.]