Who is Blackhand the Destroyer

Blackhand the Destroyer was warchief of the Horde during the first war between the Orcs and Humans. He is the one responsible for the Demonic taint on the Horde, and the inclusion of Orc Warlocks.

Under the advice of the Warlock Gul'dan, Blackhand led his Orc armies through the Dark Portal, and waged war on Humans. He managed to destroy their capital, Stormwind, but was later weakened as Gul'dan was left comatose attempting to mentally probe Medivh for information on the Tomb of Sargeras.

Blackhand was then decapitated by his second-in-command, Orgrim Doomhammer, who became the new Warchief of the Horde.