The power-hungry Gul'dan, obsessed with obtaining godhood itself, set out on a desperate search for the undersea Tomb of Sargeras that he believed held the secrets of ultimate power. Having already doomed his fellow Orcs to become the slaves of the Burning Legion, Gul'dan thought nothing of his supposed duty to Doomhammer. Backed by the Stormreaver and Twilight's Hammer clans, Gul'dan succeeded in raising the Tomb of Sargeras from the sea floor. However, when he opened the ancient, flooded vault, he found only crazed demons awaiting him.

Seeking to punish the wayward orcs for their costly betrayal, Doomhammer sent his forces to kill Gul'dan and bring the renegades back into the fold. For his recklessness, Gul'dan was torn apart by the maddened demons he had set loose. With their leader dead, the renegade clans quickly fell before Doomhammer's enraged legions. Though the rebellion had been quelled, the Horde was unable to recoup the terrible losses it had suffered. Gul'dan's betrayal had afforded the Alliance not only hope, but also time to regroup and retaliate.

Lord Lothar, seeing that the Horde was fracturing from within, gathered the last of his forces and pushed Doomhammer south, back into the shattered heartland of Stormwind. There, the Alliance forces trapped the retreating Horde within the volcanic fortress of Blackrock Spire. Though Lord Lothar fell in battle at the Spire's base, his lieutenant, Turalyon, rallied the Alliance forces at the eleventh hour and drove the Horde back into the abysmal Swamp of Sorrows. Turalyon's forces succeeded in destroying the Dark Portal, the mystical gateway that connected the Orcs to their homeworld of Draenor. Cut off from its reinforcements and fractured by infighting, the Horde finally buckled in upon itself and fell before the might of the Alliance.

The scattered Orc clans were quickly rounded up and placed within guarded internment camps. Though it seemed that the Horde had been defeated for good, some remained highly skeptical that peace would last. Khadgar, now an Archmage of some renown, convinced the Alliance high command to build the fortress of Nethergarde that would watch over the ruins of the Dark Portal and ensure that there would be no further invasions from Draenor.

The Invasion of Draenor(Warcraft 2: Beyond the Dark Portal)

As the fires of the Second War died down, the Alliance took aggressive steps to contain the Orcish threat. A number of large internment camps, meant to house the captive Orcs, were constructed in southern Lordaeron. Guarded by both the paladins and the veteran soldiers of the Alliance, the camps proved to be a great success. Though the captive Orcs were tense and anxious to do battle once more, the various camp wardens, based at the old prison-fortress of Durnholde, kept the peace and maintained a strong semblance of order.