Though Glaurung was named Father of Dragons, Ancalagon, also known as Ancalagon the Black, was the greatest of all winged dragons bred by Morgoth during the First Age, and probably the largest dragon to have ever lived.
This was the first the world had seen of winged dragons and for a time Morgoth's armies gained ground. Eärendil came out of the west in Vingilot, accompanied by the Eagles of Manwë, and they fought with Ancalagon and the other dragons. Eventually, Eärendil was victorious, and the fall of Ancalagon marked the end of Morgoth's final resistance.
Ancalagon was incredibly huge, as his wings were able to blot out the light of the sun even from afar. And when he fell from the sky, the impact shattered Thangorodrim, an artificial volcanic mountain range built above Angband.
Eärendil, on his ship Vingilot, slew Ancalagon with the aid of Thorondor and his Eagles. They fought Ancalagon for a whole day before Eärendil emerged victorious, and threw Ancalagon down upon Thangorodrim. The method in which Eärendil slew the dragon is unspecified in The Silmarillion.
Gandalf spoke of him as he told Frodo the true origin of his Ring. "It has been said that dragon-fire could melt and consume the Rings of Power, but there is not now any dragon left on earth in which the old fire is hot enough; nor was there ever any dragon, not even Ancalagon the Black, who could have harmed the One Ring, the Ruling Ring, for that was made by Sauron himself."
There were probably other dragons of supremeness, not matching Ancalagon anyway, joining the War of Wrath along with the Ancalagon.
How Eärendil and other reinforcements including great eagles managed to slay Ancalagon and his kin is logically unknown as simply speaking, there were huge differences of beyond comparing in size and war potential between these dragons and eagles. Even for Thorondor, the greatest eagle of all age. Therefore, eagles and elves could have won against foes because of supports or collaborations from the Host of Valar.
Ancalagon's characteristics share several resemblances with Carcharoth.
Gandalf might or might not have seen Ancalagon during the War of Wrath.
|Dragons of Middle-earth|
|Ancalagon | Glaurung | Scatha | Smaug | Gostir|
- ↑ The Silmarillion, Quenta Silmarillion, Chapter XXIV: "Of the Voyage of Eärendil and the War of Wrath"
- ↑ The Lord of the Rings, The Fellowship of the Ring, Book One, Chapter II: "The Shadow of the Past"
- ↑ The Complete Guide to Middle-earth