Who actually defeated Sauron in the War of the Last Alliance?

Question

From the "Tale of the Years," Appendix B of The Lord of the Rings,

3441 Sauron overthrown by Elendil and Gil-galad, who perished...

I recall there being more information about the end of the Siege of Barad-dûr, but I can't find anything, and I might be confusing the facts in my mind with the movies (darn movies). I don't own the Book of Lost Tales to do any deeper diving.

From any of the books, is there a more detailed account of what happened at the end of the Siege of Barad-dûr? Were Elendil and Gil-galad slain before Sauron died (which is what my mind thinks)? Who actually struck the blow that vanquished Sauron's physical form?

Answer 1

Isildur, possibly

NB: As stated in the edited form of the question. Sauron didn't "die" in the traditional sense, however his body died and his spirit carried on. This is covered here.

Lets go in order from The Lord of the Rings books, through to the Appendices, onto The Silmarillion and finally into the Letters. ^{_{(Emphasis mine)}}

To begin with the Council of Elrond

I beheld the last combat on the slopes of Orodruin, where Gil-galad died, and Elendil fell, and Narsil broke beneath him; but Sauron himself was overthrown, and Isildur cut the Ring from his hand with the hilt-shard of his father's sword, and took it for his own.
_{FotR: The Council of Elrond}

Elrond doesn't tell us much beyond "Sauron was overthrown". This doesn't tell us if he died before or after, but tells us that before Isildur cut the Ring off, Sauron had at least been defeated (this becomes more important later on).

In Appendix B: Tale of Years, Tolkien says that Sauron passes away after the Ring is taken from him.

Sauron overthrown by Elendil and Gil-galad, who perish. Isildur takes the One Ring. Sauron passes away ...
_{FotR: Appendix B, "Tale of Years"}

This seems to suggest that after being overthrown, Sauron remained alive, however after Isildur takes the Ring, he then perishes.

This is again supported in The Silmarillion where Sauron is described as being vanquished after the Ring was taken from him.

Sauron himself came forth; and he wrestled with Gil-galad and Elendil, and they both were slain, and the sword of Elendil broke under him as he fell. But Sauron also was thrown down, and with the hilt-shard of Narsil Isildur cut the Ruling Ring from the hand of Sauron and took it for his own. Then Sauron was for that time vanquished, and he forsook his body, and his spirit fled far away and hid in waste places
_{The Silmarillion - "Of the Rings of Power"}

However, in a letter to Milton Waldon, Tolkien contradicts what he'd said above and suggest that Gilgalad and Elendil had indeed slain Sauron and Isildur cutting the Ring from his hand freed his spirit from his body.

“It ends with the overthrow of Sauron and destruction of the second visible incarnation of evil. But at a cost, and with one disastrous mistake. Gilgalad and Elendil are slain in the act of slaying Sauron. Isildur, Elendil's son, cuts die ring from Sauron's hand, and his power departs, and his spirit flees into the shadows. [sic]
_{Letter 131 - Letters of J.R.R. Tolkien}

Saying in the act of slaying Sauron does not necessarily mean they had slain Sauron, but merely suggest that they were in the act of doing so. I don't see, however, why he'd change his opinion in his Letters before publishing the finished Lord of the Rings 3 years later.

Answer 2

He never died, only his physical form was destroyed during that Battle.

So your question would be: Who defeated Sauron in the War of the Last Alliance? The right answer would be Isildur.

As taken from https://atolkienistperspective.wordpress.com/2016/02/21/the-tale-of-the-last-alliance/ which is wholly accurate and summarises the Battle really well:

Then Gil-galad and Elendil passed into Mordor and encompassed the stronghold of Sauron; and they laid siege to it for seven years, and suffered grievous loss by fire and by the darts and bolts of the Enemy, and Sauron sent many sorties against them. There in the valley of Gorgoroth Anárion son of Elendil was slain, and many others. The helm of Anárion was crushed by the stone-cast from Barad-dûr that slew him.

But at the last the siege was so strait that Sauron himself came forth; and he wrestled with Gil-galad and Elendil. Elrond beheld the last combat on the slopes of Orodruin […]. Isildur alone stood by his father in that last mortal contest; and by Gil-galad only Círdan stood, and Elrond. With the heat of Sauron’s hand, which was black and yet burned like fire, Gil-galad was destroyed. But Sauron also was thrown down, and with the hilt-shard of Narsil Isildur cut the Ruling Ring from the hand of Sauron and took it for his own. Then Sauron was for that time vanquished, and he forsook his body, and his spirit fled far away and hid in waste places; and he took no visible shape again for many long years.

Most of the tales of the War of the Last Alliance is scattered throughout the Lord of the Rings' books (quotes found in Edlothiad's answer) and History of Middle-earth: The Return of the Shadow.

This would answer your second (a detailed account) as well.

For your third (site of Elendil and Gil-galad death) question: At that time they were participating in the Siege of Barad-dûr; so it is likely that they perished before the Barad-dûr whilst in combat with Sauron.

Answer 3

A new answer to an old question... Gil-Galad and Elendil.

Note that the question originally had 'killed' rather than 'defeated' in the title. One may debate what 'killed' actually means for a Maia, but in any case, the correct answer is given by Tolkien himself in letter 131.

Gilgalad and Elendil are slain in the act of slaying Sauron.

This matches perfectly with the (better known) text in the Council of Elrond, where Elrond says

I was at the Battle of Dagorlad before the Black Gate of Mordor, where we had the mastery: for the Spear of Gil-Galad and the Sword of Elendil, Aiglos and Narsil, none could withstand. I beheld the last combat on the slopes of Orodruin, where Gil-Galad died, and Elendil fell, and Narsil broke beneath him: but Sauron himself was overthrown, and Isildur cut the Ring from his hand...

There is also a passage in Of the Rings of Power and the Third Age which says essentially the same thing. So, in the last combat (not the last but one), Sauron was attacked by Gil-Galad and Elendil whom none could withstand (not none but Sauron), and was overthrown (meaning defeated or removed from power by force).

The main support for the Isildur theory comes from the man himself, again from Of the Rings of Power and the Third Age:

But Isildur refused this counsel [to destroy the Ring] saying: 'This I will have as a weregild for my father's death, and my brother's. Was it not I that dealt the Enemy his death-blow?' And the Ring that he held seemed to him exceedingly fair to look on; and he would not suffer it to be destroyed.

A little earlier, Of the Rings of Power and the Third Age does say that Sauron's spirit left his body after Isildur took the ring, so (from his own perspective) Isildur does have some claim to having 'killed' Sauron (whatever that actually means). However, Isildur's remark must be taken as hubris, since according to Elrond and Tolkien himself, Sauron was already slain/overthrown/thrown down. The most obvious reading is that the Ring had started work on Isildur immediately, just as it would with Smeagol many years later. Isildur was trying to legitimise his claim to be the new keeper of the One.