Over-heaven

In the cosmology of the Elves, Over-heaven was the highest of the 'airs' surrounding Arda, the domain of the stars far above and beyond the world. This was place of powerful winds, through which the Sun and the Moon moved as they passed above the lands and seas below. 'Over-heaven' was the name used for this realm by Men and Hobbits, a translation of the Elvish Tarmenel, and the Elves also commonly used the name Ilmen for the same region of the high airs.

Across the early history of Arda, there was no Sun and no Moon, so that only the stars shone down from Over-heaven, with the land of Aman alone being lit by the Light of the Two Trees. When the Two Trees were slain and the world plunged into darkness, the Valar fashioned two shining vessels from a surviving flower and fruit of the Trees. Piloted by Maiar, these vessels rose into Over-heaven to become the silver Moon and the golden Sun, and to bring light to all the lands of the world.

The paths of the newly risen Sun and Moon carried them through the lower reaches of Over-heaven, far below the ancient and distant stars. With their rising, the Years of the Sun began, much to the dismay of the Dark Lord Morgoth. He hid from the new lights in the depths of Angband, sending shadowy spirits into the high airs to assail them, but in this he failed. Ever afterward the creatures of Morgoth feared and shunned the light of the Sun.

In the closing years of the First Age, Eärendil the Mariner carried a message across the Great Sea on behalf of Elves and Men to call on the Valar for aid. At this time in history, Morgoth's dominion of Middle-earth was almost unchallenged, until the forces of the Valar fought the War of Wrath and utterly defeated the Dark Lord. Eärendil himself did not return to Middle-earth after the War. His vessel Vingilot had been hallowed by the Valar and, bearing a shining Silmaril, he set out into the sky, where a great wind carried him high. The gleaming Jewel that he bore could be seen shining down from Over-heaven as a new Star of High Hope, visible across all of Arda.