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 Eärendil 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 Nan-tathren, 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.
In those days Tuor felt old age creep upon him, and ever a longing for the deeps of the Sea grew stronger in his heart. Therefore he built a great ship, and he named it Eärrámë, which is Sea-Wing; and with Idril Celebrindal he set sail into the sunset and the West, and came no more into any tale or song. But in after days it was sung that Tuor alone of mortal Men was numbered among the elder race, and was joined with the Noldor, whom he loved; and his fate is sundered from the fate of Men.
Bright Eärendil was then lord of the people that dwelt nigh to Sirion's mouths; and he took to wife Elwing the fair, and she bore to him Elrond and Elros, who are called the Half-elven. Yet Eärendil could not rest, and his voyages about the shores of the Hither Lands eased not his unquiet. Two purposes grew in his heart, blended as one in longing for the wide Sea: he sought to sail thereon, seeking after Tuor and Idril who returned not; and he thought to find perhaps the last shore, and bring ere he died the message of Elves and Men to the Valar in the West, that should move their hearts to pity for the sorrows of Middle-earth.
Great was the sorrow of Eärendil and Elwing for the ruin of the havens of Sirion, and the captivity of their sons, and they feared that they would be slain. (...) Yet Eärendil saw now no hope left in the lands of Middle-earth, and he turned again in despair and came not home, but sought back once more to Valinor with Elwing at his side. The Silmarillion (chapters 23 and 24)