The mighty fortress carved within the fiery bowels of Blackrock Mountain was designed by the master dwarf-mason, Franclorn Forgewright. Intended to be the symbol of Dark Iron power, the fortress was held by the sinister dwarves for centuries.[1] During the First War, the Shadow Council built its secret refuge in Blackrock Spire. When the Old Horde stormed the mountain and defeated the Shadow Council, the Dark Iron dwarves under Ragnaros allowed the Horde to claim the spire as its new headquarters.[2]
However, Nefarian - the cunning son of the Dragon Aspect Deathwing - had other plans for the great keep. Nefarian and his draconic minions took control of the upper spire and made war on the dwarves' holdings in the mountain's volcanic depths. The dragon has carved out a swath of the spire and set the generals of his increasingly large army - including Rend Blackhand, the warchief of the Dark Horde - to defend the peak while he continued his sinister experiments. The spawn of Nefarian continued to creep from Blackrock Spire - and did so until the keep was broken.[3]
Eventually, Horde champions sent by Thrall invaded the Spire and killed Dal'rend, after which they proceeded to Blackwing Lair where they killed Nefarian.[4]
The upper spire was claimed by the Iron Horde, an orcish union from a parallel Draenor, as a vanguard keep and a site of a terrible scheme to unleash an iron star upon the mountain and erupt it in order to destroy surrounding areas, including the human kingdom of Stormwind as an act of revenge by Garrosh Hellscream. His ally, Zaela, Warlord of the Dragonmaw clan, is overseeing the operation alongside Tharbek, commander of the Ironmarch expeditionary forces. Some of the black dragonflight's underlings have also remained inside, such as Kyrak.
This section contains information from the Warcraft RPG which is considered non-canon.
Blackrock Spire was built by Franclorn Forgewright with the intend on making this grand fortress as the new home of the Dark Iron dwarves after the summoning of Ragnaros destroyed much of the mountain range. Nefarion, a black dragon lieutenant, had other plans, and drove the dwarves to the dungeon in his attempt to seize the fortress. He and his forces cannot take the lower depths of the complex, as Ragnaros still wields power there.
The Dark Irons shaped cooling lava to form the foundation for this fortress, and it is a wonder. Barely visible from the Molten Span, it stands black and foreboding. Dragon sentries man the walls, and the black obsidian seems to suck the light in from all surrounding areas. The dragons delight in attacking travelers, so leaving the road may be a bad idea in this area.[5]
Patch 6.0.2 (2014-10-14): Upper Blackrock Spire is now a separate instance, retuned for level 100 players, with heroic mode added. Encounters have been updated with recent storyline developments.
Patch 4.0.3a (2010-11-23): Upper Blackrock Spire is now a 5-man dungeon.
Patch 3.3.0 (2009-12-08): The minimum level requirement on the Blackrock Spire Meeting Stone has been set to level 15.
Roughly 80% of the dungeon is tuned for a single group of level 55-60 players. The top 20% of the dungeon is tuned for a very "uber" group of five, or more likely 10, level 60 players.