Later in the Second Age, Sauron gave the Nine to powerful men, "kings, sorcerers, and warriors of old". Only two of the bearers of the nine rings are identified individually. Their leader would later become the Witch-king of Angmar, and his second in command was named Khamûl, an Easterling. Khamûl was the only one to be named. Three of the Nine were Númenórean. All Nine would fall under the rings' domination, and they became the Nazgûl (Ringwraiths): spirits of terror whom Sauron could command even without the One. Their lives were extended indefinitely by the rings, and they became Sauron's chief servants, especially during the first part of the Third Age when he was too weak to act on his own behalf.

Any of these Rings of Power seemed to render a man who wore it invisible. The Nazgûl could not be seen directly by mortal eyes, but wore dark cloaks to give themselves form. Frodo saw their true form when he put on the One Ring on Weathertop.

It is not clear whether the Nazgûl continued to wear their rings. Tolkien says both "the Nine the Nazgûl keep" and that Sauron had gathered the Nine to himself, though in the latter case his meaning may be metaphorical. When the Nazgûl are destroyed, no mention is made of their rings.

See where the other "Rings of Power" are located.

                                                                       Rings of Power - The One

Rings of Power - The Nine 8FM        Rings of Power - The Seven AF7        Rings of Power - The Three - Narya
Rings of Power - The Nine CA5        Rings of Power - The Seven NAP        Rings of Power - The Three - Nenya
Rings of Power - The Nine EBP        Rings of Power - The Seven Z9Z         Rings of Power - The Three - Vilya
Rings of Power - The Nine NWB       Rings of Power - The Seven T78
Rings of Power - The Nine Q4A        Rings of Power - The Seven VNG
Rings of Power - The Nine RT1         Rings of Power - The Seven WEV
Rings of Power - The Nine TCY         Rings of Power - The Seven Y3E
Rings of Power - The Nine V2G
Rings of Power - The Nine ZBR

The Rings of Power are magical rings created by Sauron or by the Elves of Eregion under Sauron's tutelage. Three were intended for the Elves, Seven for Dwarves, Nine for Men, and one, The One Ring, was created by the Dark Lord Sauron himself in Mount Doom.

Sauron intended the rings to subvert these races of Middle-earth to his power, since The One Ring was the Ruling Ring that controlled the others. Sauron's plan was not completely successful, for the Elves hid their rings and did not use them while Sauron held The One, and the Dwarves' rings did not respond to The One's control as Sauron expected. But the nine mortal men who wore the Nine became the Nazgûl, Sauron's most dreaded weapons.