During the final days of the Second War, as the Hordeâ€™s victory over theAllianceseemed almost assured, a terrible feud erupted between the two most powerful orcs on Azeroth. As Doomhammer prepared his final assault against the Capital City of Lordaeron â€“ an assault that would have crushed the last remnants of the Allianceâ€“Gulâ€™dan and his followers abandoned their posts and set out to sea. The bewildered Doomhammer, having lost nearly half of his standing forces to Gulâ€™danâ€™s treachery, was forced to pull back and forsake his greatest chance at victory over theAlliance. The power-hungry Gulâ€™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, Gulâ€™dan thought nothing of his supposed duty to Doomhammer. Backed by the Stormreaver and Twilightâ€™s Hammer clans, Gulâ€™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 Gulâ€™dan and bring the renegades back into the fold. For his recklessness, Gulâ€™dan was torn apart by the maddened demons he had set loose. With their leader dead, the renegade clans quickly fell before Doomhammerâ€™s enraged legions.
Though the rebellion had been quelled, the Horde was unable to recoup the terrible losses it had suffered. Gulâ€™danâ€™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 Spireâ€™s base, his lieutenant, Turalyon, rallied the Alliance forces at the eleventh hour and drove the Horde back into the abysmal Swamp of Sorrows.