The "Quenta Silmarillion" tells how, in the First Age of Sun, Morgoth the Dark Enemy hid himself in the Pits of Angband and wrought his masterpieces of evil from flame and sorcery. These dark jewels of Morgoth's genius were the Great Worms called Dragons. He made three kinds: great serpents that slithered, those that walked on legs, and those that flew with wings like the Bat. Of these kinds there were two types: the Cold-drakes, who fought with fang and claw, and the miraculous Urulóki Fire-drakes, who destroyed with breaths of flame.
All Dragons were the embodiment of the chief evils of Men, Elves and Dwarves, and so were great in the destruction of those races. The Dragons themselves were vast armies that worked towards Morgoth's aims. The reptiles were of massive size and power and were protected by scale of impenetrable iron. Tooth and nail were like javelin and rapier, and their tails could crush the shield wall of any army.
The winged Dragons swept the land below them with hurricane winds, and the Fire-drakes breathed scarlet and green flames that licked the Earth and destroyed all in their path.
Beyond strength of arms, Dragons carried other more subtle powers. Their eyesight was keener than the hawk's and anything that they sighted could not escape them. They had hearing that would catch the sound of the slightest breath of the most silent enemy, and a sense of smell that would allow them to name any creature by the least odor of its flesh.
The intelligence of Dragons was renowned, as was their love of setting and solving riddles. Dragons were ancient serpents, and so were creatures of immense cleverness and knowledge but not of wisdom, for their intelligence had flaws of vanity, gluttony, greed, deceit and wrath.
Being created chiefly of the elements of fire and sorcery, the Dragons shunned water and preferred darkness to the light of day. Dragon-blood was black and deadly poison, and the vapors of their worm-stench were of burning sulfur and slime. Their bodies glowed always with a hard, gem-like flame. Their laughter was deeper than well-shafts and made the very mountains quake. The eyes of Dragons emitted rays of ruby light or in anger flashed red lightning. Their cruel reptilian voices were harsh whispers and, combined with the intensity of the serpent eye, invoked the Dragon-spell that bound unwary foes and made them wish to surrender to the beast's awesome will.
First of the Fire-drakes, the Urulóki created by Morgoth in Angband, was Glaurung, Father of Dragons. After only a century of brooding and growing in the caverns, Glaurung in fiery wrath burst out from Angband's gate and came into a startled World. Though he was not of the winged race that would later arise, Glaurung was the greatest terror of his time. He burned and savaged the lands of the Elves in Hithlum and Dorthonion before being driven back by Fingon, prince of Hithlum. Morgoth, however, was displeased with Glaurung for him impulsiveness, for he had planned that the Dragon should grow to full power before revealing him to an unsuspecting World. To Glaurung this attack was but mere adolescent adventure - a youthful testing of power. Terrible though it was to the Elves, his strength was barely developed and his scale-armour was still tender to the assault of weapons. So Morgoth held Glaurung within Angband for another two centuries before he let the Urulóki loose. This was the beginning of the Fourth Battle in the Wars of Beleriand. It became known as the Battle of Sudden Flame when Glaurung the Great Worm, in full power led Morgoth's forces into the battle against the High Elves of Beleriand. His great size and scorching fire cleared a path into the armies of foe, and with Morgoth's demons, the Balrogs, and black legions of innumerable Orcs he broke the siege of Angband and brought despair to the Elves.
In the Fifth Battle, called the Battle of Unnumbered Tears, Glaurung caused even more terrible destruction, as by now he had (in the mysterious way of Dragons) fathered a brood of lesser Fire-drakes and Cold-drakes to follow him in war. So great army of Elves and Men fell before this onslaught, and none could withstand the Dragon-flame, except the Dwarves of Belegost, who had come to fight the common foe.
Morgoth used Glaurung to hold the territories he gained; but force in battle was not the only power this monster knew. He brought many under his sway with the binding power of his serpent eye and the hypnotic Dragon-spell.
Years after Glaurung had sacked and laid waste to the kingdom of Nargothrond, the "Narn i Hîn Húrin" tells how he was slain by the mortal Túrin Turambar. For this son of Húrin came on the Fire-drake by stealth and drove the sword Gurthang deep into the beast's underbelly, but, by the poison of the black blood and the venom of the Dragon's last words, Túrin was also killed.
Though Glaurung was named the Father of Dragons, the greatest Dragon that ever entered the World was one named Ancalagon the Black. "Rushing jaws" is the meaning of his name, and his ravening majesty devestated the army of the West in the Great Battle and the War of Wrath at the close of the First Ago of Sun. Ancalagon was the first of the winged Fire-drakes, and he and others of that king came out of Angband like mighty storm clouds of wind and fire as a last defence of Morgoth's realm was made. This was the first the World had seen of winged Dragons and for a time Morgoth's foes were in retreat. Yet Eagles and all the warrior birds of the Earth came out of the West with the flying ship "Vingilot" and the warrior Eärendil. The battle of these beings of the air lasted a long time, but at last Eärendil was victorious, Ancalagon was cast down and the power of Morgoth was broken forever.
So great was the defeat of the Dragons in the Great Battle that it is not until the third Age of Sun that the histories of Middle-earth speak again of the Dragons. In that time they inhabited the wastes beyond the Gray Mountains of the North. And, it is said, their greed led them to the hoarded wealth of the Seven Kings of the Dwarves.
Mightiest of the dragons of the Grey Mountains was one named Scatha the Worm who drove the dwarves from their halls in fear and dread, but a prince of Men stood and gave a battle. This was the warrior Fram, son of Frumgar, chieftain of the Éothéd, and Scatha was killed by the hands of this Man. Yet this was but temporary release from the terror that lurked in the mountains, for in time many Cold-drakes returned to the Grey Mountains. Though the dwarves' defence was valiant and strong, they were overwhelmed; one by one their warriors fell and the gold-rich Grey Mountains were left entirely to the Dragons.
In the twenty-eighth century of the Third Age, the chronologies of the Westlands tell how the mightiest Dragon of that Age came from the North to the great kingdom of Dwarves in Erebor, the Lonely Mountain. This Fire-drake called Smaug the Golden was vast and bat-winged and a fearsome bane to Dwarves and Men. With consuming Dragon-flame Smaug ruined the city of the Men of Dale and broke the door and the wall of the Dwarf-kingdom of the Lonely Mountain. The dwarves fled or were destroyed and Smaug took the riches of that place; gold and gemstones, mithril and silver, elf-gems and pears, the many faceted crystals of emerald, sapphire and diamond. For two centuries Smaug ruled Erebor unchallenged. Yet in the year 2941 a company of adventurers came to the mountain; twelve dwarves led by the rightful king of Erebor, Thorin Oakenshield, and a hobbit mercenary who was named Bilbo Baggins. They approached the Dragon by stealth and were amazed, for Smaug was huge beyond all that they had imagined and glowed golden-red with serpent rage. He was armored as all of his race with scales of impenetrable iron, but in wariness he also protected his soft underbelly from assault; as he lay sprawled upon the wealth of his hoard he allowed diamonds and hard gemstones to imbed in his belly, and in this way armored his only weakness. Yet, by cunning the Hobbit Bilbo Baggins discovered one point upon the broad breast of the beast that was not sheathed in jewels, where sharp steel might cut.
When Smaug was aroused by the adventurers he came out in wrath and loosed his fire on the land. In vengeance he came to Esgaroth on the Long Lake, for the Lake Men had aided the adventurers. yet there lived a Northman, valiant and strong, named Bard the Bowman who, guided by the secret of the Dragon's weakness drove a black arrow into the beast's one vital place. Wondrously the Dragon screamed and fell flaming from the sky. So died Smaug the Golden, mightiest of the Dragons of the Third Age.
It was rumored that Dragons continued for many centuries to inhabit the Northern Waste beyond the Grey Mountains, but no tale that has come to Men out of Middle-earth speaks again of these evil, yet magnificent beings.