Misty Mountains Orcs

The Orcs of the Misty Mountains were tribes of Orcs settled in the tunnels in or under the mountains. They served Sauron since early on, guarding the passes and troubling the folk of Eriador. These Orcs were also responsible for the death of Isildur and the loss of the One Ring. Later on, though they harassed the peoples and regions around them on their own for a time, their bond to Sauron remained strong and even though he commanded from the far main dominions of Dol Guldur and Mordor they still carried out his will, occupying Moria and barring the paths through the mountains.
== History ==
Their origin, and when they settled those tunnels is not known. However, they recognised and hated the Gondolin-forged blades Orcrist and Glamdring, so this may indicate some awareness of the Elder Days.
== Second Age ==
Orcs who survived the War of Wrath fled to the East and harassed the Dwarves south of the Forodwaith. By the Dark Years, when Moria closed its gates the Orcs reinforced and commanded by servants of Sauron invaded the mountains again. It is said that Gundabad was re-taken (suggesting that it was again occupied by Orcs in the past).
Much later Sauron, knowing of the Last Alliance, sent many Orcs of Mordor to harry the Allied forces who would attempt to cross the Mountains. However, the main might of Gil-galad and Isildur who crossed the Pass of Imladris and the Pass of Caradhras made the Orcs to hide themselves; even Thranduil's diminished army was far too strong. The Orcs bided their time mostly hidden in Mirkwood or along the river-banks, remaining alert and watchful for companies of Elves or Men that they could outnumber. After the War of the Last Alliance, these Orcs would have no news of its outcome and Sauron's fall and they'd probably think that he won. The small detachment was eventually forgotten.
== Third Age ==
It was under the command of such Orc-chiefs from Barad-dûr they ambushed and killed Isildur at the Disaster of the Gladden Fields in early Third Age, their fierceness probably caused by the presence of the One Ring.
In T.A. 1300, the Orcs started increasing and harassing the Dwarves again.
The awakening of Durin's Bane drove the Dwarves from Moria in T.A. 1981, and Orcs of the Misty Mountains entered and occupied its ruins. Around 2480 Sauron started to populate Moria with his creatures and in the same time the Orcs begun to make secret strongholds in the Mountains so as to bar all the passes into Eriador. In 2509, on a trip to Lórien to visit her parents, Celebrian was waylaid by Orcs in the Redhorn Pass. She was captured and tormented, receiving a poisoned wound until her two sons rescued her.
Apparently Sauron forged an alliance between the Orcs and the Balchoth, a tribe of Easterlings; in the spring of T.A. 2510, Orcs and Balchoth overran Calenardhon. The Gondorian army moved against the Balchoth north of the Limlight, when a horde of Orcs from the Mountains suddenly attacked and surrounded them. The Gondorians were pressed towards Anduin until the Éothéod came to their rescue.
Around 2740, the Orcs became more bold, daring to invade Eriador. The Rangers of the North fought many battles with the sons of Elrond trying to hold them back, but one party managed to reach the Shire in 2747. They were fought off by a party of brave Hobbits under Bandobras Took, who killed their leader Golfimbul in the Battle of Greenfields.
=== War with the Dwarves ===
It seems that some Dwarves, either before or after the War of the Dwarves and Orcs, dwelt on the eastern side of the mountains near Goblin-town.
Long afterwards, Moria became the seat of an Orc-chieftain named Azog who slew King Thrór of the Longbeards, beginning the War of the Dwarves and Orcs. In 2793 the Dwarves sought revenge, assailing and sacking one by one all the Orc-holds they could from sacking Mount Gundabad in the north, to the Gladden Fields in the south. Most of the war was fought underground, in the mines, halls, and other dwellings the Orcs had occupied or created. The war ended with the Battle of Azanulbizar where Azog himself was slain, causing thousands of Orcs to flee south through Rohan, who found refuge in the White Mountains, troubling the Rohirrim for two generations.
The Orcs of the Misty Mountains virtually disappeared as a threat for Eriador and Wilderland, but the Dwarves were unable to reclaim Moria.
Gandalf believed that the Orcs drove the bears, as well as Beorn's people, from their home in the mountains. Beorn promised that one time he would return.
=== Quest for Erebor and beyond ===
The Goblin-town had a main gate in one of the passes of the Mountains from which they assaulted travellers. As that way was eventually too dangerous and abandoned, by 2941 travellers took the (seemingly safer) High Pass, so the goblins opened the Front Porch as an alternate means to snatch people.
A group of Orcs under the leadership of the Great Goblin, started planning a joint raid with the Wargs against the Woodmen to capture slaves. When they discovered Thorin and Company, they thought they were spies of those woodmen and hunted them down, fearing they would warn their people. They escaped with Gandalf's help, killing the Great Goblin in the process.
Furious, the Orcs gathered at Mount Gundabad under the command of Bolg to seek revenge and secure domination of the North. The goblins were about to sweep southward when they learned of the death of Smaug and marched by night through the mountains and appeared unexpectedly at Erebor, almost immediately after the arrival of Dáin Ironfoot, and participated the Battle of Five Armies. It ended in defeat for the Orcs (three fourths of their entire population killed), and left the Misty Mountains free of them for many years afterwards.
In 2989, Balin left the Lonely Mountain and entered Moria with other Dwarves to start a colony and restore Khazad-dûm. The company had a great battle near Mirrormere where the great chieftain was killed, allowing them to settle in Moria and explore. But the Orcs later counter-attacked, and in 2994, the entire expeditionary force was besieged and destroyed.
=== War of the Ring ===
By the time of the War of the Ring, the Beornings under Grimbeorn kept open the High Pass and the Ford of Carrock and no Orc or Wolf dared to enter his land. The Orcs of the Mountains though permanently depleted, reclaimed Moria though returning to the service of the Dark Lord Sauron.
Sauron's turncoat servant, the fallen Wizard Saruman also stirred up the Orcs tribes in the Mountains, gathering some of the forces he used against the kingdom of Rohan from there. The Orcs of Moria attacked the Fellowship of the Ring in the Battle of the Chamber of Mazarbul. Following them, a band of Orcs crossed the Nimrodel, but they were destroyed by a regiment of the Galadhrim. A company of Orcs from the Mountains joined the parties led by Uglúk and Grishnákh in ambushing the Fellowship at Amon Hen, but were later slain at night near the eaves of Fangorn by the Rohirrim. 
=== Fourth Age ===
The Longbeards under Durin VII eventually succeeded in recapturing Moria in the Fourth Age, which suggests that the Orcs of the Misty Mountains diminished.