The Broadbeams were paired with the Firebeards, when they were awakened by Eru Ilúvatar under Mount Dolmed before the First Age. They became prosperous in their great city of Belegost, trading with the Firebeards in the South, and also with the Sindar and Noldor of Beleriand, as well as the newly-appeared race of Men.
The Broadbeams were some of the greatest smiths and craftsmen in Middle Earth second only to the Dwarves of Nogrod. They invented ringed mail, and also helped build the cities of Nargothrond and Menegroth for the Elves.
In the Battle of Unnumbered Tears, the heavily-armoured Broadbeams, with their fearsome iron masks (which was a customary thing to wear in battle for their House), held off the Dragon Glaurung, as the sons of Fëanor retreated south to Ossiriand. During the battle, their Lord, King Azaghâl was killed by Glaurung. But not before wounding the dragon with a dagger in the stomach. Glaurung screamed in pain and fled, with many of the forces of Morgoth following him. Forgetting the battle, the Broadbeams then picked up their fallen ruler and taking slow steps marched home singing in a low dirge with no enemy daring to come near.
The old kingdom of the Broadbeams came to a close in the War of Wrath with the breaking of the Ered Luin and the destruction of Beleriand, which sank beneath the waves. Belegost was ruined and the city of the Firebeards, Nogrod, was totally destroyed, sinking into the sea with much of the Ered Luin. Some of the Dwarves stayed to build or rebuild new halls and mines, but most left for Khazad-dum, home of the Longbeards swelling its numbers and bringing much craft and lore.
In the Third Age it seems that the Broadbeams parted ways with Durin's folk with the Firebeards, after the awakening of the Durin's Bane, and headed back to the Ered Luin. Where some remnants of their people were still living working the mines, and where it was a safe and peaceful. During this age also the Broadbeams more than likely answered the call of Durin's folk in their great mustering for the eventual War of the Dwarves and Orcs.
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Peoples of Middle-earth, "Of Dwarves and Men", though this is an assumption based on the word-order