The Nazgûl, also known as the Ringwraiths, the Black Riders, or the Nine, were once mighty human kings who fell into darkness through the corrupting influence of the secret One Ring bestowed upon them by Sauron. When the Nine Rings of Power were forged, Sauron gave them to nine human kings to corrupt and enslave them. The Nazgûl were Sauron’s most feared servants, and they played a vital role in his plans to conquer Middle-earth.
As flying creatures, the Nazgûl were a formidable force. They could travel quickly and easily over long distances, and they were able to strike from the sky with terrifying effect. They were also immune to many forms of attack, and they could not be killed by conventional means.
The Nazgûl were used by Sauron for a variety of purposes, but their primary role was to hunt for the One Ring and its bearer. They were also used to sow fear and discord among Sauron’s enemies, and to carry out his will in all corners of Middle-earth.
The Nazgûl’s ability to fly made them especially effective at hunting down the One Ring. They could track the Ring’s bearer even over the most difficult terrain, and they could pursue them relentlessly. The Nazgûl’s flying mounts also gave them a significant advantage in battle. They could swoop down on their enemies from above, and they could easily escape if they were outnumbered or outmatched.
The Nazgûl’s ability to fly also made them a powerful symbol of Sauron’s power and reach. They were a constant reminder to the people of Middle-earth that Sauron was watching, and that he could strike anywhere at any time.
The Lord of the Rings: The Fellowship of the Ring, Book I, Chapter 2: “The Shadow of the Past”
“And the Nazgûl were abroad. They were the chief servants of Sauron, his most deadly weapons. They were the Nine Ringwraiths, neither living nor dead. They had once been mighty kings, but they had been corrupted by the Rings of Power that they had received from Sauron. Now they were his slaves, and they could only be seen when they were mounted on their fell beasts.”
The Lord of the Rings: The Fellowship of the Ring, Book I, Chapter 9: “At the Bridge of Khazad-dûm”
“Frodo looked back. The Nazgûl were coming. They were riding on fell beasts, winged shapes that were black against the moon. Frodo could see the riders’ eyes gleaming in the darkness, and he could hear their high-pitched cries.”
The Lord of the Rings: The Return of the King, Book VI, Chapter 1: “Minas Tirith”
“A great black shape swept over the city. It was a Nazgûl, riding on a fell beast. The beast had a long, serpentine body and huge, leathery wings. The Nazgûl was clad in black armor, and his face was hidden by a black hood. He carried a long sword in his hand.”