The True Horde was the name of the band of rebels who rallied against the tyrannical rule of Garrosh Hellscream, Warchief of the Horde. Although the Horde was slowly disintegrating for some time and several members were either banished or withdrawn from the organization, civil war had not begun until the secession of the Troll Empire by its leader, Vol'jin, who formed the True Horde with the Blood Elves, Forsaken, Bloodhoof Tauren and various other former Horde allies and sought to overthrow Garrosh.
Although the rebels had reached out to the Alliance for help, King Varian Wrynn turned them away, declaring the Horde's civil war as their own problem. When Thrall resurfaced, Vol'jin transferred leadership of the rebellion to him and Ogrimmar was sacked by the rebels, with Garrosh Hellscream falling at the hands of Thrall.