Long Night

In the distant depths of time, the Valar had made their original dwellings on Almaren in Middle-earth, and filled the world with light from the two great Lamps of the Valar. Melkor overthrew those Lamps, and so the Valar left Almaren, crossing the Sea into the West. In Valinor they created the Two Trees to shed Light on their own new land, but without the light of the Lamps, Middle-earth was left in darkness beneath faint stars.

This Long Night of Middle-earth persisted for millennia. The first Elves awoke beneath the starlit skies (and thus gained their name Eldar, People of the Stars), and while many departed from Middle-earth for Aman, many others remained behind in the darkness. The Night only drew to a close when Melkor destroyed the Two Trees, plunging Valinor itself into darkness and causing the Valar to create the Sun and Moon. These new lights passed over the whole of Arda, bringing their light to Middle-earth as well as Aman, and so the Long Night came to a sudden end.