Longbeards

The oldest of the seven clans of the Dwarves, founded by Durin the Deathless before the rising of the Sun and Moon, and hence also referred to as 'Durin's Folk'. In Elvish they were known as the Anfangrim.¹ The name these Dwarves used to refer to themselves, like much else about the mysterious Dwarf-tongue, remains unknown.

The first Dwarves were made in the distant past of Arda by Aulë, but were set to sleep until the first Elves had awakened. The eldest of this race was Durin, called the Deathless, who discovered the crystal lake of Kheled-zâram and chose the Mountains above the lake as a dwelling-place for his clan.

Those Mountains, known to the Dwarves as Zirakzigil, Bundushathûr and Barazinbar, became the most famous home of all the Dwarf-clans, as the rock beneath them was mined into a mighty citadel by Durin's Longbeards, a citadel known in the Dwarf-tongue as Khazad-dûm. Begun in the dark years long before the beginning of the First Age, Khazad-dûm survived through thousands of years. During the starlit years of the First Age, the power of the Longbeards spread northward to encompass the foothills of the Misty Mountains, and eastward through the Grey Mountains as far as the Iron Hills. At the end of the First Age, Dwarves from Belegost and Nogrod sought refuge there when their own cities were destroyed, making the greatest city of the Dwarves greater still. As the only known source of mithril in Middle-earth, the wealth of Khazad-dûm was spectacular.

By tradition, at times the royal house of the Longbeards would produce an heir so similar to their founder that he was also given the name of Durin. Of these, Durin III was a great friend to the Noldor who settled in Eregion to the west of Khazad-dûm, and he received a Ring of Power from Celebrimbor himself. This ring - the Ring of Durin - became an heirloom of the rulers of Durin's Folk.

The Longbeards' city was impregnable to outside attack: even Sauron's armies could not overcome its defences when they ravaged Eregion in the Second Age. It survived intact for thousands more years, but eventually it fell to a threat none of its defences could repel: a Balrog. It was afterwards known that this ancient demon had been hidden beneath the Mountains for much of Khazad-dûm's history. It had long remained undisturbed and unsuspected, but at the end of the second millennium of the Third Age, the mining Dwarves awoke it, or at least set it free. It slew many of the Longbeards, including their King, Durin VI, and his heir Náin I. Náin's son Thráin I was forced to lead his people away from their ancient and glorious mountain-city. Khazad-dûm became the Balrog's dark domain, and over the coming years Sauron filled it with his minions. Thus it acquired a new name: Moria, the Black Chasm.

After this time - the year III 1981 - the Longbeards were dispersed across the northern lands of Middle-earth, and colonies sprang up in many locations. They settled among the Grey Mountains and the Iron Hills, and Erebor, the Lonely Mountain, eventually became the seat of the Kings of Durin's Folk. There the Longbeards recovered some of their former glory, and the work of their forges made them once again wealthy and famous. Ultimately, their fame became too great: the Dragon Smaug came to hear of the Kingdom under the Mountain, and swept down from the north to claim its treasures for himself. Once again, the Longbeards were dispossessed, and scattered into the Wild.

The misfortunes of the Longbeards continued to mount. Thrór, who had been King under the Mountain before Smaug's attack, made the long journey to Moria, but he was killed there by Azog, leader of the Orc invaders. Thrór's heir Thráin II rallied support from all the other clans of the Dwarves, and began a war of vengeance: the War of the Dwarves and the Orcs. In the climactic Battle of Azanulbizar before the gates of old Khazad-dûm, the Dwarves had the victory, but the Balrog still lurked in Moria, and they could not return there.

After the battle, Durin's Folk returned to their wandering. They passed through Dunland at one time, but Thráin's son Thorin eventually led them to Ered Luin, the Blue Mountains in the far northwest of Middle-earth. There they remained for many decades, but they never forgot the Dragon that had captured their Kingdom in the east. At last, Thorin became determined to recover Erebor, and with the aid of the Wizard Gandalf and a Hobbit named Bilbo Baggins, Smaug was defeated and the Kingdom under the Mountain was re-established.

Thorin did not survive the see his Kingdom reclaimed: he died in the Battle of Five Armies that followed Smaug's defeat. The new King under the Mountain was Thorin's cousin Dáin Ironfoot, and under his leadership the Longbeards prospered once again, though they came close to ruin during the War of the Ring. Sauron's forces invaded the valley of Dale, and Dáin was slain in battle there. Retreating into the Lonely Mountain, the Dwarves and their allies were besieged. With Sauron's defeat, though, the defenders of Erebor gained new courage, and routed the invading forces.

At the end of the War of the Ring, Moria had been lost to the Dwarves for more than a thousand years. There had been attempts to return: as well as Thrór's disastrous visit, Balin had taken a force long afterwards to resettle Khazad-dûm, but his colony lasted just five years before it, was overrun by Orcs. After the War, though, the Balrog of Moria had been slain, and the master of the Orcs and Trolls had also been overcome, so the ancient home of the Longbeards lay open to recovery. It seems likely that Durin's Folk would have made a further attempt to return, though no definite record exists to confirm this.

Actually, the original drafts for Appendix A to The Lord of the Rings contain some hints that Khazad-dûm was indeed reclaimed, some centuries later, by Durin VII. This story did not survive into the published text, though, so it's unclear whether Tolkien intended it to stand.