This bitter, six-year conflict (TA 2793-99) was the first attempt of any of the Free Peoples to eliminate the Orcs of the Misty Mountains.
The hostilities between the two races began when King Thrór was murdered by Orcs of Moria. Previously, the Dwarves of Durin’s Line had been driven out of their homes in Erebor by the dragon Smaug, and their wrath had been building up when news broke out of the murder and later desecration of the king’s body. Thráin II mustered his people, and for the next six years, the Dwarves pursued the Orcs throughout Wilderland, slaughtering every one they found.
Near the end of the war, the Dwarves came to the valley of Azanulbizar (the Dimrill Dale) in Moria, where the greatest battle of the War was fought. Both sides suffered heavy losses, but reinforcements from the Iron Hills came just in time, and the Orcs who had slain Thrór had all been slain themselves; those Orcs who survived fled south in terror.