The Dwarves of Durin's Folk were ruled by six kings named Durin, all fathers and sons, until Durin VI, who was killed by Durin's Bane in 1980 of the Third Age. After his death, a king named Durin did not return to the Dwarves for many years. In the Fourth Age, a Durin VII appeared, being either the son or grandson of Thorin III. He therefore would have been a direct descendant of Durin the Deathless. Durin VII was also known as Durin the Last.
The Dwarves did not participate in any important event of history. However their friendship with the Elves perhaps became more close than ever; the Dwarves of Moria maintained close connections to the Gwaith-i-Mírdain of Eregion; the Doors of Durin of Moria were built to facilitate the communication between the two people, and was constructed jointly by both races.
In Third Age 1980, a Balrog awoke in the deeps of of the Misty Mountains and killed King Durin VI. The next year, his son Náin I was killed, and the Dwarves fled Khazad-dum, which from then on was called Moria, which means "Black pit".
Most of Durin's folk left for the Grey Mountains in the North, while some followed the new king, Thráin I, who went to Erebor on the eaves of Mirkwood in Third Age 1999 and started his kingdom there. For a little over two-hundred years the Dwarves that followed the king lived in Erebor, mining for gold and jewels and finding the most precious of jewels, the Arkenstone. When Thráin died in Third Age 2190, his son Thorin I became King under the Mountain. In Third Age 2210, when he heard that his kinsmen were gathering in the mountains to the North, and how rich and unexplored they were, he left Erebor for the Ered Mithrin.
For more than 300 years the Dwarves of the Grey Mountains prospered. After many years, however, the Dragons in the far North started to gain strength; their population grew, and they made war against the Dwarves, plundering and destroying their works. At last, in Third Age 2589, King Dáin I, along with his second oldest son Frór, was killed at the gates of his halls by a great Cold-drake.
Once again the Dwarves were exiled from their homes. Most of the Dwarves left the Ered Mithrin. Some followed Dáin's youngest son Grór to the Iron Hills, while most one being the king's brother Borin followed the the new king Thrór to Erebor again to start a new Kingdom under the Mountain.
For over 200 years Durin's folk prospered, having friendship with Men who dwelt near; the Men of Dale were able to drive away all enemies from the East, until the dragon Smaug descended upon Erebor in Third Age 2770; not long after the kingdom was destroyed and Smaug made for himself a bed of gold in the Great Hall. Many of of the Dwarves escaped the sacking, last of all King Thrór with his son Thráin II from a secret passage. The King decided to wander South along with a small company of family and followers, while most of the survivors went to the Iron Hills.
Eventually Durin's folk settled in Dunland, and in Third Age 2790 King Thrór gave to his son the Last of the Seven Rings of the Dwarves, and departed with his old friend Nár; they travelled North over the Redhorn Pass to the East-gate of Moria, where he entered proudly into the ancient kingdom, demanding to return it. But he was met by the Goblins of Moria, and their king Azog cut his head, calling him a beggar. The head of the dwarven king was given to Nár (who hid before the Gate few days and waited), and on it was written "AZOG". Nár returned to Thráin and tell him everything. Enraged, Thráin, now the King of Dwarves, called to all the Houses of Dwarves to war, to avenge his father. Thus began the War of Dwarves and Orcs, in which the Dwarves destroyed all the Goblin strongholds in the Misty Mountains one by one, until they came to the East-gate of Moria, where the great Battle of Azanulbizar was fought. In this battle all the dwarven clans united, but the Goblins were still slowly winning, until at last help came - Náin son of Grór came with fresh Dwarven forces from the Iron Hills. The Battle ended with the victory of Dwarves, but at great cost. Náin was slain by Azog, but his son Dáin avenged him by killing Azog. Thráin wanted to enter Khazad-dûm, but the other Dwarven clans would not, and Dáin also warned him of the Balrog of Moria that he felt when he came close to the Gate.
Then Thráin came to the Blue Mountains and established his realm there, doing everything to increase its wealth, power and numbers. But in him still was rage - now that he had his revenge on the Goblins, he now was eager of the Lonely Mountain and its wealth, and also to revenge Smaug. Soon after, he left the Blue Mountains to his son Thorin, and started traveling to Erebor with a group of Dwarves. His company returned, but he did not. He was taken by the Necromancer to Dol Guldur, and there he was long held in the dark dungeons. Gandalf met him, and Thráin, although not able to even remember his name, gave him a map and key of Erebor before his death.
Thorin became the King of Dwarves, and ruled in the Blue Mountains for some time. But soon he, by chance of destiny, met Gandalf at Bree. There Gandalf told him about his father Thráin, and Thorin desided to make a quest to Erebor. He gathered around him twelve dwarves, mostly from his own line, and he was joined by Gandalf and Bilbo Baggins. The Quest of Erebor ended with the death of Smaug at the hands of Bard the Bowmen. With the hoard unguarded, Thorin claimed it fully. The Elves of Mirkwood and Men of Dale demanded part of the treasures, which Thorin refused. Then he asked help from his cousin Dáin from the Iron Hills, and he came with five hundred Dwarven warriors. The Dwarves united with the Elves and Men when the Goblins came, and fought the Battle of Five Armies. With the death of Thorin and his sister-sons Fíli and Kíli, the kingship under the Mountain passed to Dáin.
Some time during the Fourth Age, Durin VII reestablished the kingdom of Khazad-dum.
Durin's Folk also seemed to have a small remnant of its people in the Grey Mountains after the main population left.
Line of Durin's Folk
- Durin I (The Deathless), father of Dwarves. Founder and first King of Khazad-dum.
- Durin II Durin Reincarnated.
- Durin III started a friendship with the Elves of Eregion during his reign, and was the first to recieve one of the Seven Dwarf-rings.
- Durin IV Lead a host of Dwarves from Khazad-dum in the War of the Last Alliance
- Durin V Durin reincarnated.
- Durin VI son of Durin V. He was killed by Durin's Bane in T.A. 1980
- Náin I son of Durin VI. Last King of Khazad-Dûm, he was killed by Durin's Bane in 1981 T.A.
- Thráin I son of Náin I. Founded Erebor in T.A. 1999
- Thorin I son of Thráin I. He left Erebor for the Ered Mithrin
- Glóin son of Thorin I
- Óin son of Glóin
- Náin II son of Óin
- Dáin I son of Náin II. The last King to rule the Dwarves of the Grey Mountains, he was killed by a great Cold-drake in T.A. 2589
- Thrór son of Dáin I. Returned to Erebor as King in Exile, and later tried to reclaim Moria. He was killed by Azog the Orc in T.A. 2790 (Beginning of the War of the Dwarves and Orcs)
- Thráin II son of Thrór. Made his kingdom in the northern range of the Ered Luin. He tried to go claim Erebor once again, but was captured by Orcs and taken to the dungeons of Dol Guldur in T.A. 2850, and was the last bearer of Durin's ring.
- Thorin Oakenshield son of Thrain II. He was the king of Durin's Folk in the Blue Mountains, until he refounded Erebor, but was killed in the Battle of Five Armies in T.A. 2941. He is the only known Longbeard King to die childless.
- Dáin II Ironfoot (grandson of Grór), who was killed in the War of the Ring in T.A. 3019
- Thorin III Stonehelm Dáin's son became king and had either a son or grandson who became...
- Durin VII, who refounded Khazad-dûm in the Fourth Age
Historically "Longbeards" is the supposed original name of the Lombards, but other than the name, there is no other significant similarities between the Lombards and the Durin's Folk.