The Lay of Leithian – Canto VII J. R. R. Tolkien

When Morgoth in that day of doom
had slain the Trees and filled with gloom
the shining land of Valinor,
there Fëanor and his sons then swore
the mighty oath upon the hill
of towered Tirion, that still
wrought wars and sorrow in the world.
From darkling seas the fogs unfurled.
their blinding shadows grey and cold
where Glingal once had bloomed with gold
and Belthil bore its silver flowers.
The mists were mantled round the towers
of the Elves' white city by the sea.
There countless torches fitfully
did start and twinkle, as the Gnomes
were gathered to their fading homes,
and thronged the long and winding stair
that led to the wide echoing square.

There Fëanor mourned his jewels divine,
the Silmarils he made. Like wine
his wild and potent words them fill;
a great host harkens deathly still.
But all he said both wild and wise,
half truth and half the fruit of lies
that Morgoth sowed in Valinor,
in other songs and other lore
recorded is. He bade them flee
from lands divine, to cross the sea,
the pathless plains, the perilous shores
where ice-infested water roars;
to follow Morgoth to the unlit earth
leaving their dwellings and olden mirth;
to go back to the Outer Lands
to wars and weeping. There their hands
they joined in vows, those kinsmen seven,
swearing beneath the stars of Heaven,
by Varda the Holy that them wrought
and bore them each with radiance fraught
and set them in the deeps to flame.
Timbrenting's holy height they name,
whereon are built the timeless halls
of Manwë Lord of Air. Who calls
these names in witness may not break
his oath, though earth and heaven shake.