Eles eram homens com grande poder no mundo mortal, e Sauron deu-lhes os Nove Anéis e os amarrou a ele.
De Portal de Tolkien (referenciado ao Silmarillion , Contos Inacabados , e os Apêndices ao Senhor dos Anéis :
Sometime during the Second Age (after year S.A. 1600) Sauron gave nine Rings of Power to powerful mortal Men. It is said that three of the Nine were lords of Númenor corrupted by Sauron, and one was a king among the Easterlings.
For many years the bearers used the rings to gain great wealth, prestige and power, becoming "mighty in their day, kings, sorcerers, and warriors of old". The effect of the rings caused their lives to be prolonged, and to see things of the Unseen. But over time their bodily forms faded until they became wraiths entirely, slaves under the domination of Sauron's One Ring.
Known as the Nazgûl, they first appeared around S.A. 2251 and were soon established as Sauron's principal servants.