War Chief from Warcraft I
The Warchief, or War Chief, is the military leader of the Orcish Horde, similar to a king or Supreme Allied Commander among humans. The post is an ancient tradition, but was forgotten during the civil wars that plagued Draenor following the defeat of the Draenei. After the Horde crossed into Azeroth, Gul'dan revived the office to gain control of the orcs. On Draenor, Ner'zhul took the title in the event Gul'dan should ever return. The Warchief is now the title of the Horde's supreme leader, though his duties no longer include simply war.
In Warcraft: Orcs & Humans, it is a rank you can achieve.
Warchiefs of the Horde[]
Gul'dan - Warchief of the First Horde during the orc's demon influenced war on the Draenei.
Blackhand — Warchief of the Horde (Rise of the Horde; Warcraft: Orcs and Humans)
Orgrim Doomhammer — Warchief of the Horde (Warcraft II: Tides of Darkness; Lord of the Clans)
Ner'zhul — Warchief of the Horde of Draenor (Warcraft II: Beyond the Dark Portal)
Thrall — Warchief of the Horde (Lord of the Clans; Warcraft III: Reign of Chaos; Warcraft III: The Frozen Throne; World of Warcraft; World of Warcraft: The Burning Crusade; World of Warcraft: Wrath of the Lich King)
Other Warchiefs[]
Other organizations have warchiefs as well. At present, there are two individuals who use the title in World of Warcraft — one in Azeroth, the other in Outland. Both are enslaved by a power greater than themselves.