Witch-king of AngmarThe Witch-king of Angmar - The Witch-king of Angmar was Lord of the Nazgûl and originally a sorcerer.  He conquered the northern kingdom before being driven out of Angmar at the Battle of Fornost.  After that, he fled to Morder and took up residence in Minas Morgul.

 

"The lord of that land was known as the Witch-king, but it was not known until later that he was indeed the chief of the Ringwraiths, who came north with the purpose of destroying the Dúnedain in Arnor, seeing hope in their disunion, while Gondor was strong." ~The Return of the King (Appendix A)