From WoWWiki
The Blackrock clan led the charge during the First War and Second War. During that time period, it was one of the largest and most feared of the orc clans. During the Third War a faction of the clan tried to summon demons, while other group is still fighting the Alliance and are known as the Dark Horde.
History
First War
Near the end of the First War, Blackhand was challenged and killed by his lieutenant, Orgrim Doomhammer. Doomhammer seized control of the clan and slaughtered the members of the Shadow Council, the biggest threat to his throne.
Second War
The clan's forces achieved a number of victories during the Second War, though the betrayal of Gul'dan forced Doomhammer to divide his forces and send a part of the clan to hunt down Gul'dan and slaughter his followers. The event weakened the Blackrocks, who were eventually defeated and nearly destroyed during the assault on Blackrock Spire and Orgrim Doomhammer was himself captured and sent to Lordaeron in chains. The Blackrock clan did not disappear though, the few remaining orcs who had not been captured or killed at the battle returned to Blackrock Spire and began to rebuild. Unlike the other orcs, they remained steadfast to the ideals of the old Horde, including demon worship, and depraved blood lust. They became a beacon for orcs who longed for the old days, and soon enough their ranks began to swell again.
Third War
In the intervening years between the Second War and Third War, the Blackrock clan became a major problem for the Alliance. A faction in Lordaeron under the leadership of Jubei'thos re-embraced their demon-worshipping heritage,[2] staged raids on a number of defenseless Alliance towns[3] and sacrificed their villagers to the Legion because their warlocks told them that demons would rain from the skies and the world would burn (referring to the coming of the Burning Legion in the following months).[2] They ignored Thrall's call to return to shamanism.[4] During the Third War, most of the Blackrock forces in the Lordaeron were killed by Arthas and Kel'Thuzad's Scourge. Jubei'thos and his lieutenants had in their possession a demon gate which Kel'Thuzad needed to communicate with Archimonde.[5] The Blackrock orcs that Thrall didn't liberate from the human's internment camps were likely killed by the scourge.[4]
Aftermath of the Third War
Currently, the Blackrock clan still mainly resides in and around Blackrock Spire under the leadership of Rend Blackhand, where they war with the Dark Iron dwarves for control of the area. Their holdings also include territory in the Burning Steppes and the Redridge Mountains. They have formed the Dark Horde and have become a dire threat to nearby towns like Lakeshire, whose defenses are severely strained against their raids. It has also been rumored that they have allied with a group of black dragons led by Nefarian, Deathwing's son. They are but one of the pawns Nefarian is using to undermine the human kingdom of Stormwind.
Blackrock clan divisions
Lordaeron divisions
Azeroth classes
Known members
References
Goraluk Anvilcrack
Rend Blackhand
Blackhand the Destroyer
Griselda
Jubei'Thos
Orgrim Doomhammer
Telkar Doomhammer
