The sorrow of the Elves is they live beyond their time
‘Til all the world forgets them, save in tales and rhyme.

Arafel, “Tree of Swords and Jewels”, Mercedes Lackey filk based on C.J. Cherryh novel of same name

“Sing, you said.” Thaliell’s voice held no laughter in it, ringing high and harshly from the canopy of stone branches stretched overhead. “Laugh. For we are those who have stayed true to what we are, forsaking neither our land nor our ways! Moths who follow torches, you called them, the Restless, who went there and back again, and brought their feuds and hopeless causes with them. Our songs and hunts and feasting you called greater treasures than light trapped in jewels, their vile attempts to ape the Powers with things they shaped but did not truly create. And now you would bid us cut the trees of Middle-earth to fashion ships, abandon all we have, and follow them, become them, when the Shadow is lifted at last?”
“Are you finished, Laswathel?” the Elvenking asked grimly.
“Look, the chickadee is scolding the hawk,” said one of the spectators lounging against the columns. A few begin to make up a lively tune:
Why fly ye south, the Chickadee said,
When leaves are gold and sky is clear,
You have a nest to rest your head,
Why leave you now your forest dear?
The mockingbird did laugh and dance–
Thranduil held up his hand, and the singers piped down reluctantly, a few titters echoing around his audience chamber.
Red-faced, Thaliell stood with back straight and hands clenched at her sides, one booted toe upon the dais of his throne. Her hair was gold like many of those in Greenleaves, including the king’s; few now remembered that this was a marvel, for his lineage came from Outside. It had helped his father win their hearts long ago: a high lord of the Sindar renouncing the wars and troubles of the nobler kindreds, calling the Wood-elves pure and free, not ignorant and rustic as they were accounted by those who had grown great in power, wisdom, and sorrow.
“Yes, my lord,” she muttered, the reminder of her lost brother doing little to improve her temper.
He rose from his chair of carven stone, one of the few signs of the world he had left behind: Wood-elves did not dwell in stone halls hewed by dwarves; that was a precaution and luxury that Thranduil had learned from Thingol. Moreover, he called himself King. King of a shunned land, king of a lesser race, but the Elvenking, in these days when the High-elves and their High Kings were history, and Thingol a memory only to Thranduil himself. “There are two paths for us,” he stated. “To dwindle here, while Men wax in power and slowly erode our forests, our world, changing it as we ourselves change until we are a pathetic ghost of what we were– or to seek new forests in a land that does not change. I would not abandon Middle-earth, were there any other way. But it will soon forsake us. We cannot hold to what we are, if we stay.”
“What nonsense is this?” Thaliell scowled up at him. “You have been listening to their mad Queen’s prophecies, or some such ‘higher lore’. Perhaps the Eldar have some reason to fear, but why should we? They’re just afraid they’ll lose their powers and become like us again, living in harmony with the seasons. We have autumn and spring; I’ll wager there’s none where they’re going.”
There was an air of indulgent boredom in the grand chamber; few of the Elves were paying much attention to her gripes or the king’s strange and cryptic warnings. Thranduil could at times be a grim lord, despite his family’s adoption of the Wood-elves’ relaxed lifestyle, and his mutterings tended to be tolerated rather than heeded. By his counsel they had been saved from Dol Guldur’s shadow, moving north instead of fighting the long defeat with the rest of their race. But they did not know the sorrows and hardships they had all but missed; stories like Amroth’s were for them just pretty ballads. The memory of the years of horror, the Last Alliance when two thirds of them had died, had faded. Even the Battle of Five Armies was seldom mentioned anymore. They had always remained eerily isolated from the heavy cares of their kindred, and the house of Oropher had encouraged them to remain so.
“I wished to shield you,” he said softly. “From orc, fire, grief, and knowledge of these things. But in the end I cannot hold back time, not even were I to take up a Ring like the one She used to keep Lórien preserved like a deer’s head stuffed and dried and pinned to a wall. And my son is gone. I am sorry, Thaliell.”
“Lord–”
He lifted the wreath of autumn leaves and berries from his hair and set it upon his seat. “I am no longer your lord,” he said flatly. “Follow or do not follow. I have told you why. You must decide for yourselves.”
The singers were busy again as he strode from the hall, brushing past his daughter who stood frozen, staring at the Elvenking’s crown.

O, where are we going? O, where are we going?
The seagulls are playing, the oarsmen are rowing!
The river is singing, the sea-winds are blowing!
Come, follow me south
To the shore and the mouth
Of Anduin!
Come, follow me west
Where the forests are best
In Aman!

So they were still singing as the last of the boats were dragged down to the river and set afloat with a splash, amid laughter and the last of the wine from Dorwinion. Their hunting dogs romped in the river’s edge and raced along the shore, kicking up mud. It comforted Thaliell a little, to see how such drastic change did not seem to matter to her people any more than their hounds.
She stood in the edge of the new clearing they had made, cutting birch and oak for the pretty gray boats that now bobbled like a flock of geese in the water. Swans, she remembered, were the symbol of Lórien and their westernmost kin, but geese suited the gaggle of laughing Wood-elves pushing off from the shore, as if setting out on one more hunt or a visit to Dale and Lake-town. Maybe Aman could not change them, and her grandfather’s mistrust of the West had been groundless.
Almost Thaliell began to walk down to them, but she squared her shoulders. Her decision was made.
Thranduil had his arm around her and was watching them. “It’s time,” he murmured, that word which was almost a curse to them. “Will you not come, Thaliell? It breaks my heart to abandon you here, alone.”
“I’ll be fine.” She smiled and kissed his cheek. “I have the beeches, and the whole of Greenwood, and there’s Men to tease if I grow weary of my own voice. Give my brother greetings.”
He sighed. “Perhaps it’s better that one of us remains: Middle-earth will be a lesser place when the last Elf is gone. Whatever becomes of you, Thaliell, I am proud.” He touched the wreath of ivy in her hair. “You are Queen, now,” he teased.
“Get on, gloomy eyes,” she chided. “Get to your land of peace and light and joy, or whatever pretty nonsense it is my brother spouted in your ear the last time we saw him. Maybe the bliss of Aman can stop even you from fretting.”
“Thaliell–”
“Look after them, my lord,” she murmured in his ear. “Don’t let them change.”
“In Aman we never will.” His grey eyes met hers: the one visible sign that they were not the same blood as the rest of the Silvan folk. She nodded slightly. The Wood-elves might not even realize how profound the change was, when they had come to Aman, leaving seasons and mortal lands behind forever. They would take the world however it came to them. They must.
Reluctantly Thranduil let her step away. There was a certain amount of hooting and whistles from the boatsmen; they were waving cheerfully at Thaliell. Few really understood that they would not see her again. It was better that way.
The last king of the Elves east of the Sea, king no longer, strode to the boat at the head of the vast flotilla, leapt in, and cast off the hawser binding it to shore. Only on his cheeks were there tears.
Thaliell stood alone at the edge of Greenwood the Great, Lasgalen, the wood of Greenleaves, named for her brother but not as Men would know it; and their name for it, Mirkwood, would outlast all the others. Across the river was Lórien. But it was a ghost now. The last few golden leaves rattled on the branches, although the Mallorns used to cling tenaciously to theirs until the new green came. As I will, she vowed. But they did not look like Mallorns now. The great-girthed, queenly trees with bark of smooth silvery grey were no more than beeches, fairest trees of forest. And she had those a-plenty near Thranduil’s empty halls.
Thaliell turned her horse northward and did not bother to watch her people vanish in the cold and foggy dawn.