Ban of the Valar

The Númenóreans were forbidden by the Valar from sailing so far westward that Númenor was no longer visible, for fear that they would come upon the Undying Lands, to which Men could not come. Over time the Númenóreans came to resent the Ban of the Valar and to rebel against their authority, seeking the everlasting life that they believed was begrudged them. They tried to compensate for this by going eastward and colonizing large parts of Middle-earth, first in a friendly way, but later as tyrants. Soon the Númenóreans came to rule a great but terrorizing maritime empire that had no rival. Few (the "Faithful") remained loyal to the Valar and friendly to the Elves.