In the spring of the year after was born in Gondolin Earendil Halfelven, the son of Tuor and Idril Celebrindal; and that was five hundred years and three since the coming of the Noldor to Middle-earth. Of surpassing beauty was Earendil, for a light was in his face as the light of heaven, and he had the beauty and the wisdom of the Eldar and the strength and hardihood of the Men of old; and the Sea spoke ever in his ear and heart, even as with Tuor his father.
Then the days of Gondolin were yet full of joy and peace; and none knew that the region wherein the Hidden Kingdom lay had been at last revealed to Morgoth by the cries of Hurin, when standing in the wilderness beyond the Encircling Mountains and finding no entrance he called on Turgon in despair. Thereafter the thought of Morgoth was bent unceasing on the mountainous land between Anach and the upper waters of Sirion, whither his servants had never passed; yet still no spy or creature out of Angband could come there because of the vigilance of the eagles, and Morgoth was thwarted in the fulfilment of his designs. But Idril Celebrindal was wise and far-seeing, and her heart misgave her, and foreboding crept upon her spirit as a cloud. Therefore in that time she let prepare a secret way, that should lead down from the city and passing out beneath the surface of the plain issue far beyond the walls, northward of Amon Gwareth; and she contrived it that the work was known but to few, and no whisper of it came to Maeglin's ears.
Now on a time, when Earendil was yet young, Maeglin was lost. For he, as has been told, loved mining and quarrying after metals above all other craft; and he was master and leader of the Elves who worked in the mountains distant from the city, seeking after metals for their smithying of things both of peace and war. But often Maeglin went with few of his folk beyond the leaguer of the hills, and the King knew not that his bidding was defied; and thus it came to pass, as fate willed, that Maeglin was taken prisoner by Orcs, and brought to Angband, Maeglin was no weakling or craven, but the torment wherewith he was threatened cowed his spirit, and he purchased his life and freedom by revealing to Morgoth the very place of Gondolin and the ways whereby it might be found and assailed. Great indeed was the Joy of Morgoth, and to Maeglin he promised the lordship of Gondolin as his vassal, and the possession of Idril Celebrindal, when the city should be taken; and indeed desire for Idril and hatred for Tuor led Maeglin the easier to his treachery, most infamous in all the histories of the Elder Days. But Morgoth sent him back to Gondolin, lest any should suspect the betrayal, and so that Maeglin should aid the assault from within, when the hour came; and he abode in the halls of the King with smiling face and evil in his heart, while the darkness gathered ever deeper upon Idril.
At last, in the year when Earendil was seven years old, Morgoth was ready, and he loosed upon Gondolin his Balrogs, and his Orcs, and his wolves; and with them came dragons of the brood of Glaurung, and they were become now many and terrible. The host of Morgoth came over the northern hills where the height was greatest and the watch least vigilant, and it came at night upon a time of festival, when all the people of Gondolin were upon the walls to await the rising sun, and sing their songs at its uplifting; for the morrow was the great feast that they named the Gates of Summer. But the red light mounted the hills in the north and not in the east; and there was no stay in the advance of the foe until they were beneath the very walls of Gondolin, and the city was beleaguered without hope. Of the deeds of desperate valour there done, by the chieftains of the noble houses and their warriors, and not least by Tuor, much is told in The Fall of Gondolin: of the battle of Ecthelion of the Fountain with Gothmog Lord of Balrogs in the very square of the King, where each slew the other, and of the defence of the tower of Turgon by the people of his household, until the tower was overthrown; and mighty was its fall and the fall of Turgon in its ruin.
Tuor sought to rescue Idril from the sack of the city, but Maeglin had laid hands on her, and on Earendil; and Tuor fought with Maeglin on the walls, and cast him far out, and his body as it fell smote the rocky slopes of Amon Gwareth thrice ere it pitched into the flames below. Then Tuor and Idril led such remnants of the people of Gondolin as they could gather in the confusion of the burning down the secret way which Idril had prepared; and of that passage the captains of Angband knew nothing, and thought not that any fugitives would take a path towards the north and the highest parts of the mountains and the nighest to Angband. The fume of the burning, and the steam of the fair fountains of Gondolin withering in the flame of the dragons of the north, fell upon the vale of Tumladen in mournful mists; and thus was the escape of Tuor and his company aided, for there was still a long and open road to follow from the tunnel's mouth to the foothills of the mountains. Nonetheless they came thither, and beyond hope they climbed, in woe and misery, for the high places were cold and terrible, and they had among them many that were wounded, and women and children.
There was a dreadful pass, Cirith Thoronath it was named, the Eagles' Cleft, where beneath the shadow of the highest peaks a narrow path wound its way; on the right hand it was walled by a precipice, and on the left a dreadful fall leapt into emptiness. Along that narrow way their march was strung, when they were ambushed by Orcs, for Morgoth had set watchers all about the encircling hills; and a Balrog was with them. Then dreadful was their plight, and hardly would they have been saved by the valour of yellow-haired Glorfindel, chief of the House of the Golden Flower of Gondolin, had not Thorondor come timely to their aid.
Many are the songs that have been sung of the duel of Glorfindel with the Balrog upon a pinnacle of rock in that high place; and both fell to ruin in the abyss. But the eagles coming stooped upon the Orcs, and drove them shrieking back; and all were slain or cast into the deeps, so that rumour of the escape from Gondolin came not until long after to Morgoth's ears. Then Thorondor bore up Glorfindel's body out of the abyss, and they buried him in a mound of stones beside the pass; and a green turf came there, and yellow flowers bloomed upon it amid the barrenness of stone, until the world was changed.
Thus led by Tuor son of Huor the remnant of Gondolin passed over the mountains, and came down into the Vale of Sirion; and fleeing southward by weary and dangerous marches they came at length to Nan-tathren, the Land of Willows, for the power of Ulmo yet ran in the great river, and it was about them. There they rested a while, and were healed of their hurts and weariness; but their sorrow could not be healed. And they made a feast in memory of Gondolin and of the Elves that had perished there, the maidens, and the wives, and the warriors of the King; and for Glorfindel the beloved many were the songs they sang, under the willows of Nan-tathren in the waning of the year. There Tuor made a song for Earendil his son, concerning the coming of Ulmo the Lord of Waters to the shores of Nevrast aforetime; and the sea-longing woke in his heart, and in his son's also. Therefore Idril and Tuor departed from Nantathren, and went southwards down the river to the sea; and they dwelt there by the mouths of Sirion, and joined their people to the company of Elwing Dior's daughter, that had fled thither but a little while before. And when the tidings came to Balar of the fall of Gondolin and the death of Turgon, Ereinion Gil-galad son of Fingon was named High King of the Noldor in Middle-earth.