“The dark fire will not avail you, flame of Udûn. “—Gandalf to Durin’s Bane on the Bridge of Khazad-dûm , The Lord of the Rings, The Fellowship of the Ring
Durin’s Bane is a Balrog. Balrogs, also known as the Valaraukar, were Maiar that were seduced and corrupted by Melkor(Morgoth) into his service. But this Balrog was named Valarauko “Demon of Might”, later named Durin’s Bane by the Dwarves. The Balrog killed King Durin VI when the Dwarves were mining for mithril deep inside Moria and awoke him.
Durin’s Bane is oddly enough a Maiar spirit which existed before the Middle Earth was created. That being said, This Balrog is the same as Gandalf and Saruman, who descended into Arda with the Valar. I believe I’ve touched base on this over the last couple of post of the Middle Earth Challenge. But the Balrog was corrupted by Morgoth in the first age of Middle Earth. Durin’s Bane fought in a number of battle notably most of the War of the Jewels tot he vary end of the battle of War of the Wrath. Where Durnin’s Bane managed to escape to the Misty Mountains. Deep, Deep underground that would be Khazad-dûm.
All through out the second age of Middle Earth, more than five thousand. Till the third age came about and the Dwarves mined to to deep in their greed for meithril. Woke the Balrog and it killed Durin VI and then his son Náin I after a number of fail attempts to the Balrog. Later the Durin’s Folk left Khazad-dûm and renamed it Moria. Now we all know the big fight be Durin’s Bane and Gandalf that started at the Bridge of Khazad-dûm.
Ralph Bakshi’s The Lord of the Rings
The Balrog appeared in Raph Bakshi’s Animated Lord of the Rings. Is appears as a giant Humanoid with a lion’s head and wings. Gandalf is the only one that seems to recognize it, and it does not appear until The Fellowship reaches the Bridge of Khazad-dûm.
Peter Jackson’s The Fellowship of the Ring
The Balrog was also portrayed in Peter Jackson’s live-action film trilogy, as a giant, black creature covered in flame. Although Tolkien described it as being taller than a man but not huge, Durin’s Bane in the film is at least twenty feet tall. Rather than having a voice of any kind, when it roared, it sounded similar to an erupting volcano – the vaporous presence of heat emanating as its breath (the Balrog’s roar was created by pulling a cinderblock across a plywood board and then digitally shifting the pitch of the resulting sound.) Unlike previous adaptations, the goblins are terrified, and run as it comes closer to The Fellowship. Its weapons, rather than physical in nature, were completely comprised of flame, taking the form of a sword first and a whip second. Its own flames were its key weapon of choice against Gandalf. Their duel progress closely to how it does in the book: Gandalf shatters the Balrog’s fiery sword (using a magical shield formed around himself in conjunction with Glamdring), and then strikes bridge of Khazad-dûm, breaking it in half, and causing the Balrog to fall into the abyss. As the Balrog falls, its whip latches onto Gandalf’s legs and drags him off of the bridge.
Aside from this, the Balrog had been briefly seen in a book owned by Saruman, beforehand, as the latter taunted Gandalf telepathically of the choice of the Fellowship taking the route of Moria, implying that Saruman was aware that it had awoken and brought woe to the Dwarves there.
The Two Towers
The Balrog appears in a few flashbacks in The Two Towers. The first flashback shows the events that take place following Gandalf’s plunge into the abyss of Khazad-dûm: Gandalf hurtles down the chasm after the Balrog, recovering his sword Glamdring in midair and catching up to the Balrog. He and the Balrog attempt to kill each other as they continue to fall down the abyss, with Gandalf managing to land several blows on the Balrog while it makes constant attempts to strike at Gandalf with its fists and claws. They fall for a few minutes, until they at last crash violently into the underground lake, temporarily extinguishing the Balrog’s flames.
The second flashback shows Gandalf and the Balrog now dueling atop Mount Zirakzigil during a great storm, in which Gandalf manages to imbue his sword with electricity from a lightning strike and stabs the Balrog through the heart, mortally wounding it and causing it to fall from the peak and crash onto the mountain side, its flames extinguished.