The War of the Dwarves and Orcs was a significant series of battles between the conflicting parties. It lasted from TA 2793-2799 in the Misty Mountains of Middle-earth.
Pre-history
Dwarves fighting the Orcs.
In TA 2790, the ancient Dwarf King Thror, a descendent of Durin, traveled with his comrade Nár to the lost kingdom of Moria. Upon their arrival in the East Gate, Nár convinced King Thror not to go inside for the dangers looming in its darkness. But King Thror persisted, claiming his inheritance to the ancient Dwarf kingdom. Nár remained outside Moria's gate for days, but Thror never came back. Three days passed, then Nár witnessed Azog the Orc toss King Thror's dead body out of the gates of Moria and onto the stairs of the entrance, with the name of Azog incised upon the face of the Dwarf King.The Orc shouts for Thror's companion, to tell everyone of his deed. Azog threatened that whoever attempts to trespass Moria will have the same death. He declared that because he murdered Thror, then he was indeed the new king of Moria. The forces of Azog hindered Nár to recover the head of the King, and even threw him a bag of coins with no value, as a sign of mockery. He grasped the coins and escaped. As he turned to look one last time at Thror.
He saw goblins out of the entrance and ripping the body, throwing the flesh for the ravens to eat. Afterward, Nár arrived in Dunland and reported the tragic end of Thror to his son Thráin II. Thráin cried in anguish and later refused to speak in his mourning. A week later, he suddenly got up and shouted that he could not bear it, and called to set forth scouts to all Dwarves, spreading news of the tragedy that transpired. From TA 2790 to TA 2793, the kin of Durin, also called Longbeards, retaliated through gathering their armies, calling forth other Dwarf clans as the degradation of the most ancient house of the Dwarves greatly enrage them.
Dispute
In TA 2793, all the Dwarves united and moved, destroying all the goblin realms of the Misty Mountains. They began in the north's Mount Gundabad through the summit of Methedras. Almost all the battle was deep below the ground as the Dwarves fiercely sought Azog. It was forbidding and relentless at this point of the war that some seasoned Dwarf warriors never spoke of the events that occurred. In TA 2799, the culmination of the war was on the Battle of Azanulbizar, a blood bath between the Dwarves and Orcs on Moria's entrance. The army of the Iron Hills arrived at the end of the battle, thus giving victory to the Dwarves. Afterward, Thráin II, son of Thrór, wished to proceed inside Moria and take back the old kingdom. But their comrades, who were of other clans and not Longbeards, declined. They have fought to avenge the house of Durin, and they consider the war's triumph sufficient. They also dread that Durin's Bane (the Balrog) still lives, and were hesitant to proceed as it remains in Moria. As the war concluded, the Dwarves followed Azog to the eastern entrance of Moria. Dáin Ironfoot kills Azog, avenging his father Náin, whom the Orc just killed. They put the head of Azog on a stake, and on his mouth, they shoved the same bag of coins he threw to Nár from nine years ago when he killed King Thror.
"That was the beginning of the War of the Dwarves and the Orcs, which was long and deadly, and fought for the most part in deep places beneath the earth. Thráin at once sent messengers bearing the tale, north, east, and west; but it was three years before the Dwarves had mustered their strength. Durin's Folk gathered all their host, and they were joined by great forces sent from the houses of other Fathers; for this dishonour to the heir of the Elders of their race filled them with wrath. When all was ready they assailed and sacked one by one all the strongholds of the Orcs that they could from Gundabad to the Gladden. Both sides were pitiless and there was death and cruel deeds by dark and by light. But the Dwarves had the victory through their strength, and their matchless weapons, and the fire of their anger, as they hunted for Azog in every den under mountain. At last all the Orcs that fled before them were gathered in Moria, and the Dwarf-host in pursuit came to Azanulbizar. That was a great vale that lay between the arms of the mountains about the lake of Kheled-zâram and had been of old part of the kingdom of Khazad-dûm. When the Dwarves saw the gate of their ancient mansions upon the hill-side they sent up a great shout like thunder in the valley. But a great host of foes was arrayed on the slopes above them, and out of the gates poured a multitude of Orcs that had been held back by Azog for the last need. At first fortune was against the Dwarves; for it was a dark day of winter without sun, and the Orcs did not waver, and they outnumbered their enemies and had the higher ground. So began the Battle of Azanulbizar (or Nanduhirion in the Elvish tongue), at the memory of which the Orcs still shudder and the Dwarves weep.