In the final battle, Frodo and Gollum fight and ultimately the Ring falls into the molten lava. The instant that the Ring is destroyed, Sauron knows it has been destroyed by his actions as the Eye.

But what is more, the army currently fighting knows the instant that it has been destroyed and starts to run in vain:

How did the army know that the Ring was destroyed?

  • 29
    Well... I'd say when the tower your boss sits in starts crumbling, it's a good idea to move away. Feb 19, 2017 at 12:55
  • @Gallifreyan, it was a little more instant than that.
    – KyloRen
    Feb 19, 2017 at 12:57
  • 1
    I see. Another question: where did that scar on Aragorn's face come from? Feb 19, 2017 at 13:06
  • 22
    It's the Mystical Scar of Pooreditor
    – Valorum
    Feb 19, 2017 at 13:20
  • 4
    "...Sauron knows it has been destroyed by his actions as the Eye." I think it's more accurate to say the Eye was having an "Oh crap!" moment. :-)
    – RichS
    Feb 19, 2017 at 17:47

4 Answers 4


It was Sauron's power, intimately connected to that of the Ring, which fuelled them.

Here's the actual text of the book describing what happens to the host at the Black Gate during the events at Orodruin:

But the Nazgûl turned and fled, and vanished into Mordor’s shadows, hearing a sudden terrible call out of the Dark Tower; and even at that moment all the hosts of Mordor trembled, doubt clutched their hearts, their laughter failed, their hands shook and their limbs were loosed. The Power that drove them on and filled them with hate and fury was wavering, its will was removed from them; and now looking in the eyes of their enemies they saw a deadly light and were afraid.

-- The Return of the King, Part 2, Chapter 4: The Fields of Cormallen (emphasis mine)

Plus, the event was so cataclysmic that its effects were visible from a great distance.

Then rising swiftly up, far above the Towers of the Black Gate, high above the mountains, a vast soaring darkness sprang into the sky, flickering with fire. The earth groaned and quaked. The Towers of the Teeth swayed, tottered, and fell down; the mighty rampart crumbled; the Black Gate was hurled in ruin; and from far away, now dim, now growing, now mounting to the clouds, there came a drumming rumble, a roar, a long echoing roll of ruinous noise.

‘The realm of Sauron is ended!’ said Gandalf. ‘The Ring-bearer has fulfilled his Quest.’ And as the Captains gazed south to the Land of Mordor, it seemed to them that, black against the pall of cloud, there rose a huge shape of shadow, impenetrable, lightning-crowned, filling all the sky. Enormous it reared above the world, and stretched out towards them a vast threatening hand, terrible but impotent: for even as it leaned over them, a great wind took it, and it was all blown away, and passed; and then a hush fell.

The Captains bowed their heads; and when they looked up again, behold! their enemies were flying and the power of Mordor was scattering like dust in the wind. As when death smites the swollen brooding thing that inhabits their crawling hill and holds them all in sway, ants will wander witless and purposeless and then feebly die, so the creatures of Sauron, orc or troll or beast spell-enslaved, ran hither and thither mindless; and some slew themselves, or cast themselves in pits, or fled wailing back to hide in holes and dark lightless places far from hope. But the Men of Rhûn and of Harad, Easterling and Southron, saw the ruin of their war and the great majesty and glory of the Captains of the West. And those that were deepest and longest in evil servitude, hating the West, and yet were men proud and bold, in their turn now gathered themselves for a last stand of desperate battle. But the most part fled eastward as they could; and some cast their weapons down and sued for mercy.

-- The Return of the King, Part 2, Chapter 4: The Fields of Cormallen (emphasis mine)

  • 11
    I think the first paragraph is really enough - some evil force/presence vanished from the world and everybody felt it. Rationalization is a rabbit hole leading to midichlorians and we definitely do not want to go that way ;-).
    – Edheldil
    Feb 20, 2017 at 12:37
  • Whilst I agree with the conclusion that Sauron's power fuelled his army, it is clear from The Return of the King, part 2 chapter 3 "Mount Doom" that the cause of the reaction you quote from chapter 4 is Frodo putting on the ring and claiming it as his own, not the destruction of the ring. This goes for the original question too, the armies quailed as Sauron's attention was diverted to the peril at Mount Doom.
    – Sam
    Feb 21, 2017 at 1:43
  • Yes, it helps to read the book. Sep 24, 2019 at 11:52

Since your question has a film clip, it's worth examining what's going on in the movie version. The troll and the orcs are distracted by the awful sounds emanating from Mordor, then flee as they see the Tower of Sauron implode and the "foundations of Mordor" begin to collapse.

CLOSE ON: The RING sits on the river of LAVA for a brief moment, then SINKS away . . .





On the BATTLEFIELD, all eyes turn to MOUNT DOOM ...

ANGLE ON: The CAVE TROLL, with ARAGORN at his mercy, is distracted by the SOUNDS emanating from MORDOR . . . he turns in TERROR and RUNS OFF . . .


ANGLE ON: The FELLOWSHIP turn to watch as the MASSIVE DARK TOWER of SAURON shakes itself to pieces!

TOWERS FALL and WALLS CRUMBLE; vast spires of SMOKE and spouting STEAM billow up!

The FOUNDATIONS explode apart ...


The BLACK GATES collapse in a huge cloud of ASH!

THE ORCS are FLEEING in all DIRECTIONS . . . As the very foundations of MORDOR collapse!

Movie Script - Return of the King - Jackson/Boyens

  • 11
    "The CAVE TROLL, with ARAGORN at his mercy" ... sigh. Did the films really put in crap like that just to add some cheap momentary suspense?
    – Rand al'Thor
    Feb 19, 2017 at 13:58
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    @Randal'thor - Every single chapter of "The Hobbit" ends on a cliffhanger.
    – Valorum
    Feb 19, 2017 at 14:03
  • Yes to this. Also, directly after the ring sinks into the lava, they can all see that the Eye basically bursts into flame. This is when they begin to panic.
    – robopuppy
    Feb 19, 2017 at 15:31
  • 2
    @robopuppy but, the eye was always flame... and in that scene, Barad-dur crumbles and the flame is extinguished (see 1:28ish in the extended edition).
    – user31563
    Feb 20, 2017 at 8:03
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    @Valorum: Just done a quick scan of The Hobbit, and I find: End by resolving tension (6 chapters): Chapters 1, 2, 5, 6, 9, 19. End by moving into new phase with little or no tension (5): 3, 10, 14, 16, 18. End by moving into new phase with moderate tension (7): 7 (Queer lodgings), 8 (Files & Spiders), 11 (On the Doorstep), 12 (Inside Information), 13 (Not at Home), 15 (The Gathering of the Clouds), 17 (The Clouds burst). End on cliff-hanger (1): 4 (Over hill & under hill).
    – PJTraill
    Feb 20, 2017 at 22:19

The army didn't necessarily know, but the army was driven by Sauron's will. When he focused his thoughts elsewhere, on the ring itself, moments before it was destroyed, his army already halted.

And far away, as Frodo put on the Ring and claimed it for his own, even in Sammath Naur the very heart of his realm, the Power in Barad-dûr was shaken, and the Tower trembled from its foundations to its proud and bitter crown. The Dark Lord was suddenly aware of him, and his Eye piercing all shadows looked across the plain to the door that he had made; and the magnitude of his own folly was revealed to him in a blinding flash, and all the devices of his enemies were at last laid bare. Then his wrath blazed in consuming flame, but his fear rose like a vast black smoke to choke him. For he knew his deadly peril and the thread upon which his doom now hung.
From all his policies and webs of fear and treachery, from all his stratagems and wars his mind shook free; and throughout his realm a tremor ran, his slaves quailed, and his armies halted, and his captains suddenly steerless, bereft of will, wavered and despaired. For they were forgotten. The whole mind and purpose of the Power that wielded them was now bent with overwhelming force upon the Mountain. At his summons, wheeling with a rending cry, in a last desperate race there flew, faster than the winds, the Nazgûl, the Ringwraiths, and with a storm of wings they hurtled southwards to Mount Doom.

The Return of the King, Part 2, Chapter 2: "Mount Doom" (emphases mine)

In addition to the quotes in other answers, this clearly shows his armies were driven by Sauron's mind, Sauron's will. They didn't feel the destruction of the Ring itself, they felt Suaron's mind withdraw as a result.


Like others have stated, the Eye knew instantly because it was literally extinguished and the tower it sat on crumbled. This is because the Eye was the last life he had, his physical body had died long ago, and his existence was tied to the Ring. When it was destroyed, Sauron was too. Moreover, the armies knew not only because they could see and hear what was happening, but they could feel the presence of the Ring, and when it was destroyed they knew that they didn't have any more hope because there was nothing for them to fight for.

  • I don't think this adds anything to the previous answers? Feb 21, 2017 at 10:10

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