Ered Mithrin or Grey Mountains was a large mountain range to the north of Rhovanion. The Grey Mountains were the last remnants of the wall of the Ered Engrin or Iron Mountains, which once stretched all over the north of Middle-earth, but were broken at the end of the First Age.
The ridge of the Grey Mountains
Description[]
The Grey Mountains were the last remnants of the wall of the Iron Mountains or Ered Engrin, which once stretched all over the north of Middle-earth, but were broken at the end of the First Age after the War of Wrath. North of the Grey Mountains lay Forodwaith, or the Northern Waste. This land was known as Dor Daidelos during the First Age, but most of it was destroyed in the breaking of Arda after the War of Wrath.
In the maps of the Second and Third Age it may look like the Grey Mountains were but a northern arm of the Misty Mountains, but in truth this mountain range was far older, stemming from the creation of Arda, whereas the Misty Mountains had not been raised until after the Years of the Lamps.
Where the Grey Mountains met at their western end with the Misty Mountains lay Mount Gundabad, an ancient Dwarven holy site and the place where Durin I awoke.
The stretch of mountains west of the Misty Mountains which still formed one range with the Grey Mountains was known as the Mountains of Angmar, another remnant of the Iron Mountains.
The eastern end of the Grey Mountains was split into two branches, and in between lay the Withered Heath, where dragons still bred. After that was a long gap, until the Iron Hills continued the old line of the Iron Mountains again. The Lonely Mountain, or Erebor, was not part of either range and was entirely separate.
From East to West the mountains stretched some 350 Númenórean miles, and the sources of the Great River Anduin, Langwell, the river Greylin, and the Forest River of Mirkwood arose in this range.
In the First Age, the Longbeards established mansions in Moria and the Iron Hills, and they considered the Grey Mountains, which lay between these mansions, to be within their territory. Some Men—mostly related to the House of Hador of Beleriand—settled between the Grey Mountains and Greenwood, and they allied with the Longbeards against Morgoth's Orcs. This alliance ended in the Second Age after Sauron destroyed Eregion, which prompted the Longbeards to seal Moria. During this time, Orcs took control of the Grey Mountains.
Durin's Folk started to gather in the Grey Mountains in T.A. 1981 after a Balrog was awakened in their ancestral home of Khazad-dûm, which its people fled in fear. Another portion of Durin's folk lead by King Thráin I established the Kingdom under the Mountain in T.A. 1999 at Erebor.
Around T.A. 2000, Scatha, a mighty Long-worm of the Grey Mountains and one of the greatest Dragons to infest that range of the north, had plundered treasure from the Dwarves and kept it in his hoard. He was slain by Fram son of Frumgar in the early days of the Éothéod. His recovered hoard was the subject of great dispute between the Men and Dwarves of the Grey Mountains, who claimed the hoard as their own.
During the Watchful Peace most of Durin's Folk were gathering to the Grey Mountains and in T.A. 2210 Thorin I abandoned Erebor and also joined the others. Nearly six hundred years later, Dragons began afflicting the Dwarves. In 2589 Dáin I was slain by a Dragon and the Grey Mountain strongholds were abandoned after the Wars of the Dwarves and Dragons. About 2480 Orcs had begun to infest the Misty Mountains and spread to the Grey Mountains, such that by 2941 Gandalf the Wizard could say that the range was "simply stiff with goblins, hobgoblins, and orcs of the worst description". However, after the Battle of Five Armies the number of Orcs in the Grey Mountains were greatly reduced (some three parts of them had perished).
There still was a remnant of the Dwarves in the Ered Mithrin after the core of the population left, but were probably few; working whatever mines they could hold from the Orcs and Dragons.