In their origins, Elves and Men were given two separate and different fates: the Elves were 'immortal', or at least they remained in the world for the long millennia until its end. Men, though, were made mortal, and after a few short decades they would leave the world and pass out of the knowledge of Valar and Elves alike. This was not at first seen as a fearful thing, and the idea of death was referred to as the Gift of Men, to be accepted freely by each at the proper time.

As the shadow of Morgoth spread darkness throughout Middle-earth, so Men came to see death not as a Gift, but as a thing to be feared or even - if it were possible - escaped. After this time, it became known as the Doom of Men. The later Númenóreans, despite their long lives, showed a particular fear of their fate, clinging to life until its last moments, and housing their preserved dead in great tombs. At last, driven on by Sauron, King Ar-Pharazôn led an immense army in an attempt to wrest the Undying Lands from the Valar, and achieve their unending life for himself. His hopeless quest for immortality brought its opposite to his people: Númenor was utterly destroyed, and the Doom of Men was visited upon all its inhabitants.