King of Dúrin's Folk was the title given to the head of Dwarven clan called the Longbeards. The first of these rulers were inhabitants of Khazad-dûm long descended from Durin. They ruled and lived there for thousands of years until TA 1980 when miners awoke the Balrog Felagrog which eventually drove out the Dwarves. Afterwards, its successors lived elsewhere and founded other kingdoms such as places like Erebor, Ered Mithrin, and Ered Luin.
- The Lord of the Rings: The Fellowship of the Ring (First appearance)