Orgrim Doomhammer

From wow.incgamers.com

Chieftan of the Orc Thunderlord Clan and friend of Durotan. After Medivh was slain by the Humans, Doomhammer seized the opportunity and killed the current Warchief Blackhand the Destroyer and took total control of the Horde as Warchief. Under Doomhammer the Horde decimated Northshire Abbey, Goldshire and Moonbrook and finally Stormwind Keep defeating the Humans.

Doomhammer executed almost all members of the Shadow Council, for consorting with demons. Among the surviving members of the Shadow Council, Gul'dan managed to beg for his life, and be spared.

Doomhammer led the orcs through the Second War over the Great Sea, and in to Lordaeron and Quel'thalas. He was then betrayed by Gul'dan, who took a third of the standing forces to search for the Tomb of Sargeras, which effectively lost him the war.

After dealing with the insurgents, they retreated back towards Blackrock Spire, and ambushed the pursuing Alliance forces. Orgrim killed the Alliance Supreme Commander, Anduin Lothar in single battle, but was defeated by Turalyon shortly after. The Alliance forces got renewed power, and defeated the Orcish Horde, following them to the Dark Portal.

Orgrim was captured by the Alliance, but later escaped, becoming a hermit. When Thrall escaped his imprisonment, he med Orgrim in disguise, and he taught Thrall many things of his experiences. He died when freeing orcs from internment camps set up by the Alliance, and gave the title of Warchief to Thrall.