Kingdom under the Mountain

The Kingdom under the Mountain was the name given to the Dwarf realm of Erebor. It was founded in T.A. 1999 when Thráin I came to the Lonely Mountain and discovered the Arkenstone. The kingdom lasted until 2770, when Smaug the Dragon invaded and either killed the Dwarves or forced them to leave. When Smaug was slain in 2941, Dáin Ironfoot became King Dáin II and the kingdom was restored.
== History ==
While mining for mithril in T.A. 1980, the dwarves of Khazad-dûm awoke a Balrog and it killed King Durin VI. Many Dwarves died defending their city, including Durin's oldest son and heir, King Náin I. In T.A. 1981, the next in line, Thráin I, fled with the rest of his people.
Thráin, with those who would follow him, went to the colony in the Lonely Mountain in T.A. 1999 where he made himself King under the Mountain, and relocated the capital of the Longbeards. Under Thráin's rule the Arkenstone was discovered, and many riches were mined from its depths; After Thráin's death and his son Thorin I had ruled for ten years, he abandoned the Mountain in T.A. 2210 for the Grey Mountains; where his people were now gathering.
=== Decline ===
After King Thorin left the mountain was once again a colony, and its status as capital city was transferred to the Ered Mithrin.
It was nearly four hundred years before Durin's folk returned in mass to the Lonely Mountain. The reason for this being that the Dwarves of the Grey Mountains had been fighting a war against the Dragons, who had plagued the Dwarves for hundreds of years. In the year T.A. 2589 King Náin II and middle son Frór were killed by a great Cold-drake at the entrance to their halls, which led to the decision by the two remaining heirs, Thrór and Grór, to leave the mountains with those who wished to follow them,
=== Re-establishment ===
The following year the now king Thrór, led a group back to the Lonely Mountain, while his brother Grór led another portion to the Iron Hills, and even some stayed behind in the Ered Mithrin.
Thrór eventually made it to the Lonely Mountain, and declared himself King under the Mountain. Under Thrór's rule the Lonely Mountain once again became the capital of Durin's folk, the Dwarves of Erebor became the best smiths and masons in Wilderland, trade increased with their kinsman in the Iron Hills and elsewhere, and they also became very rich.
=== Sack of Erebor and exile ===
But with this new found prosperity came trouble. It wasn't long before the great dragon Smaug heard of their great wealth, and one day decided to take their treasure for himself. In the year T.A. 2770, Smaug descended on the mountain in a ball of fire. He killed King Girion of Dale with many of his knights, and he killed a large amount of the Dwarves living in the mountain. Most of the survivors fled to the Iron Hills, others went with the royal family into exile, and some simply went their own way.
While Durin's folk wandered from the mountain to Dunland to the northern Blue Mountains; they ever longed for the halls of the Lonely Mountain.
=== Quest of Erebor and restoration ===
In T.A. 2941, with Gandalf's council, Thorin Oakenshield and a company of twelve dwarves, with the help of the Hobbit Bilbo Baggins, undertook the Quest of Erebor and retook the city and treasure. In the meantime the Dragon Smaug went to destroy Esgaroth, only to be killed by a man named Bard.
Thorin was free to proclaim himself King under the Mountain. However the mountain was besieged by the Men of Esgaroth and the Elves of Mirkwood, who wished recompensation for the damage done by the dragon. Dáin Ironfoot arrived to support Thorin, but a great host of Orcs and Wargs came to take the mountain. Then the Elves, Men, and Dwarves were united and fought against them. After Thorin's and his nephews' deaths, Dáin was made King of Durin's folk and of the mountain. Finally after so many years of longing the Longbeards finally returned to the Lonely Mountain.
=== Prosperity and War of the Ring ===
Under Dáin's rule the Dwarves of the Lonely Mountain became very rich and prosperous. They rebuilt the town of Dale, their trade greatly increased with their kinsman in the Iron Hills once again and with Men; and the Lonely Mountain was restored to its original greatness. But once again trouble began to brew in the east. The Men of Dale were nearing war with the Easterlings, and in the year T.A. 3019 an emissary from Sauron came to Dáin and said that if he were to give up the location of Bilbo (who had discovered the Ring of Power in his travels) that Sauron would return to him the three remaining Dwarven rings. But being wary of the emissary, Dáin sent his kinsmen Glóin to Rivendell to warn Bilbo that Sauron was after him.
Several months later the Dwarves aided the Men of Dale who defended them against Easterlings. The Battle of Dale lasted for 3 days until they were forced to retreat into the Mountain; King Brand and King Dáin were killed at its very gates. The Dwarves and Men held out for several days until the besieged came forth from the Lonely Mountain, and drove the attackers back to the East, never to be bothered again.
After the death of his father, Thorin III Stonehelm became King of Durin's folk and King-under-the-Mountain. Ambassadors were sent to the crowning of the King Elessar, and both kingdoms remained friends of Gondor, subjects of the King of the West.