What were the names of the Nazgul?
The only known text to name any of the Nazgul is “The Hunt for the Ring” in Unfinished Tales. It names “the second to the Chief, Khamul the Shadow of the East” as Sauron’s lieutenant in Dol Guldur; in a previous draft, he was called “the Second Chief (the Black Easterling)”. Some believe that Gothmog, the lieutenant of Morgul, was also a Nazgul; see question III.B.13 for further discussion. Some people have used the name “Angmar” to refer to the Witch King. We know of no instance in which Tolkien used “Angmar” as a personal name; in his writings it always refers to the Witch King’s country. Some still defend the use of “Angmar” as a convenient nickname, but as others find this irritating it is probably best avoided.
