Dwarves of the Blue Mountains
After the War of Wrath, much of the Ered Luin fell into the sea, taking the Dwarf city of Nogrod home of the Firebeard Dwarves with it (which later became the Gulf of Lhún), and ruining Belegost to the south, the home of Broadbeams. Many of the Firebeards and Broadbeams left the Ered Luin for Khazad-dum, while some stayed to help rebuild what they could of what later became the northern halls of the Dwarves, and the remnants of Belegost in the southern chain.
For thousands of years the Dwarves toiled in the Blue Mountains. Working the lesser mines and rebulding what was left of their ancient kingdom,