Anar

During the Years of the Trees, Valinor was lit for many thousands of years by the light of the Two Trees, silver Telperion and golden Laurelin. When these were destroyed by Melkor and Ungoliant, Valinor was plunged into darkness. Through the power of Nienna and Yavanna, though, Laurelin produced a single fiery fruit before it died. This golden fire was set in a vessel, and steered into the sky by the Maia Arien. The Vanyar gave it the name Anar the fire-golden: this was the origin of the Sun.

Valinor was in the West of the World, and so the first sunrise was in the west, not the east. Originally, Arien was to have steered Anar ceaselessly from west to east and back again, always remaining in the sky, but the Valar changed this counsel, so that each evening Anar would descend into the distant western seas, and re-emerge each morning in the east.