The Nazgûl (also known as ringwraiths) are the ring servants of lord Sauron (aidansebastian) they once were nine great Kings of Men, but after they were all given Rings of Power. The Nine took them, and they became servants of Sauron, and later on his chief lieutenants, once he gained control through his newly forged One Ring. After a long time the effect of the rings of power left the kings spectral, invisible to all but those who could see into the wraith world (such as high elves or the bearer of the One Ring).
So far there are eight Nazgûl serving aidansebastian. BDdeuce , The Witch-king and leader of the Nazgûl, the other of the chosen Nazgûl are: Faylynn King of Angmar , The Gundabad War Chiefs Lord_Morghash_IV and Iluvatars_Bane, the Gundabad Captain Morgul_Lord, the Uruk-hai Ghash_Max, FlimmFlamm, and Clay2816, and finally the Easterling Tchri006.