"We are the Orcish Horde. The True Horde! We die, bloody and thrashing on the field of battle, like true Orcs should." - Garrosh Hellscream
The True Horde was a variation of the Horde envisioned by Garrosh Hellscream. The True Horde was centered around Orcish superiority, which resulted in oppression and eventual attacks on other races of the Horde. Because of these acts, Garrosh became a target for both the New Horde and the Grand Alliance. Garrosh attempted to use the powers of an Old God, Y'shaarj, to empower certain members of the Horde, but very few could manage to master such power. Garrosh also hired the aid of Blackfuse Company, which provided Garrosh with powerful siege weapons.
During the Siege of Orgrimmar, many members of the True Horde were imprisoned or killed in the battle. Garrosh himself was confronted by Thrall, and eventually defeated. Upon an agreement by Thrall and Varian Wrynn, Garrosh would be put on trial in Pandaria.
Despite the Siege's results, the True Horde was not yet finished. Warlord Zaela had survived the battle, and was intent on freeing Garrosh. Gathering the remaining members of the True Horde that she could find, Zaela attacked the court that held Garrosh on trial, and with the aid of Kairoz, helped Garrosh escape.
"True Horde" is a common name used to define various Hordes, but only Garrosh's Horde has been referred to only as the "True Horde", aside from an Orcish Horde.