Nain

Warning: Wikipedia contains spoilers

Náin is the name of two Kings of Durin's Folk.

Náin I was the son of Durin VI, and succeeded his father as King of Khazad-dûm. When his father was slain by the Balrog, Náin I attempted to destroy it, but was himself killed the following year. The remainder of Durin's Folk fled Khazad-dûm, and renamed it Moria.

Náin II was another King of Durin's Folk, son of Óin[?]. Under Náin II, the Dwarves lived in the Grey Mountains, until they were attacked by dragons. He was succeeded by his son, Dáin I[?].