THE SECOND AGE II: MORE SECONDER
Ar-Pharazon’s first big act as king was to conquer Mordor, Operation DESTROY ALL EVIL FOREVER. He assembled a big army of Edain and allied Men (Elves were not invited to participate) and invaded Mordor and rolled up to Sauron’s palace and Sauron took one look at the situation and surrendered. Ar-Pharazon then, against the advice of everyone around him, chained Sauron up and took him back to Numenor as a prisoner. This was back when Sauron was basically a dude, specifically a handsome and aristocratic gentleman. I’m picturing Donald Sutherland.
So Sauron was a prisoner in Numenor, and at first he was chained up and mocked, but through flattery and cunning he ended up Ar-Pharazon’s chief advisor. Everyone who thought this was a bad idea was declared a traitor and kicked to the curb, including the leader of the Faithful and Sauron’s personal nemesis, the young Numenorean politician Elendil.
Ar-Pharazon eventually got old, and worried about death, and Sauron suggested that he invade the Undying Lands and demand the gift of immortality from the angels, which Ar-Pharazon thought was a great idea. Elves thought that was a bad idea, so it must be a good idea, is how he saw it. Ar-Pharazon assembled another fleet, even bigger than the one he used to conquer Mordor, and set out to conquer the Undying Lands in the Uttermost West. The trip was slow and uneventful, and eventually the fleet came within sight of the Undying Lands. No resistance so far, to the disappointment of the Numenorean fleet and all their warships. They’d expected a big naval battle in their conquest of heaven, but no. The angels watched, waited, did nothing. When Ar-Pharazon had the temerity to actually step on Valinor, though, this was one step too far for them.
So the angels killed everyone and sunk Numenor.
Boom, flooding, massive death, everybody dies. The only refugees were a group of Faithful who evacuated the island prior to the ill-fated expedition, Elendil and his followers. They arrived in Gondor with a magical white tree and the seven seeing-stones, the Palantir, which are about all the relics they were able to grab on their way out.
Elendil and his sons established the kingdoms of Gondor and Arnor, and the capital cities of Osgiliath and Annuminas, and set about rebuilding civilization. They were optimistic, because they assumed Sauron was dead and Morgoth gone and there was no more Shadow to oppress them.
But no, Sauron survived, kind of, as a disembodied spirit, thanks to the rings he’d made (again, though, the rings don’t get a mention until Appendix B) and he went back to Mordor and rebuilt and attacked the Men as quickly as he could, so as to prevent them from getting well-established. He would have destroyed them, too, except that Elendil and his son Isildur were able to convince the remaining elves, particularly Gil-Galad the Elfking, to ally with them against Sauron. And there was another big war, the Last Alliance, and the One Ring was cut from Sauron’s hand, and the Second Age ended.
Fun fact: Isildur was not Elendil’s only son! In fact Elendil had three other sons, all older than Isildur. Isildur was born in Rivendell, after the evacuation and sinking of Numenor. The other three sons died in the Last Alliance.