Nazgûl

The Nazgûl (from Black Speech 'ring', and 'wraith, spirit')introduced as Black Riders and also called Ringwraiths, Dark Riders, the Nine Riders, or simply the Nineare fictional characters in J. R. R. Tolkien's Middle-earth. They were nine Men who had succumbed to Sauron's power through wearing Rings of Power, which gave them immortality but reduced them to invisible wraiths, servants bound to the power of the One Ring and completely under Sauron's control.

The Lord of the Rings calls them Sauron's "most terrible servants". Their leader, known as the Witch-king of Angmar, the Lord of the Nazgûl, or the Black Captain, was Sauron's chief agent for most of the Third Age. At the end of the Third Age, their main stronghold was the city of Minas Morgul at the entrance to Sauron's realm, Mordor. They dress entirely in black. In their early forays, they ride on black horses; later they ride flying monsters, which Tolkien described as "pterodactylic". Their main weapon is terror, though in their pursuit of the Ring-bearer Frodo Baggins, their leader uses a Morgul-knife which would reduce its victim to a wraith, and they carry ordinary swords. In his final battle, the Lord of the Nazgûl attacks Éowyn with a mace. The hobbit Merry Brandybuck stabs him with an ancient enchanted Númenórean blade, allowing Éowyn to kill him with her sword.