Established long before the Great Sundering, the Gurubashi Empire took its name from the strongest tribe of jungle trolls at the time. The jungle trolls ruled the southern jungles of ancient Kalimdor until the Burning Legion's first invasion, which wrought havoc and devastation throughout the continent and culminated in the Great Sundering.
The long centuries following the Sundering were difficult ones for the troll race. The jungle trolls, driven to desperate ends, enlisted the aid of the god Hakkar, also known as the Soulflayer. Hakkar brought the trolls great power, but in return the bloodthirsty god required that souls be sacrificed to him.
His demands quickly escalated, and he grew impatient with his loyal priests, the Hakkari. He told them to find a way to summon him physically into the world, so that he might directly drain the blood of his victims. Most of the Hakkari were horrified at the idea, but the Atal'ai, a small extremist faction of the Hakkari, decided to do as Hakkar wished.
Before the Atal'ai could complete the summoning, the other jungle trolls, including the Hakkari, rose up in open revolt against the cruel god. Even the Zandalar tribe was drawn into the conflict, which finally ended with the destruction of Hakkar's avatar. Driven from the jungles, the Atal'ai were hunted nearly to extinction. Yet a small group of Atal'ai escaped into the Swamp of Sorrows, where they secretly built a great temple to their god: the Temple of Atal'Hakkar. The Hakkari, too, were killed or exiled for the evil deeds they had done in Hakkar's name, despite the fact that they had fought the Atal'ai. In great bitterness and despair, the surviving Hakkari tracked the Atal'ai to the Swamp of Sorrows and pledged to help the Atal'ai summon Hakkar into Azeroth. Pleased by the Hakkari's obvious suffering, the Atal'ai welcomed their former brethren into the temple.
In recent years the exiled Atal'ai have discovered that Hakkar's physical form can only be summoned within the ancient capital of the Gurubashi empire, Zul'Gurub. Jammal'an the Prophet, leader of the Atal'ai, told his people that if they succeeded in bringing Hakkar physically into Azeroth, then Hakkar would grant the Atal'ai immortality. The Atal'ai and Hakkari lost no time in dispatching a number of their most skilled priests to Zul'Gurub, where their efforts met with success at last. Numerous spies have confirmed the presence of the dreaded Soulflayer in the heart of the ruins. Word of his reappearance reached the Gurubashi tribe, which had lost much of its power and prestige since Hakkar's avatar on Azeroth was destroyed. The Gurubashi eagerly returned to the capital to prove themselves to Hakkar and perhaps recapture their former glory.
According to several reports, Hakkar has enthralled five high priests of the trolls' primal gods. Unable to oppose his will, the priests are channeling the power of their gods into Hakkar. Only their deaths can sever the connections that are vastly increasing Hakkar's might while draining the other gods of power.
Word of Hakkar's presence reached the Zandalar tribe in the South Seas, and they were horrified to discover the enslavement of their kindred, the Zandalari high priests. King Rastakhan has therefore sent emissaries from the island of Zandalar to the Eastern Kingdoms, where the trolls recruit champions from Azeroth's many races in the hope that Hakkar will once again be defeated.
The Gurubashi tribe is convinced that the Soulflayer will restore the Gurubashi empire in return for the tribe's loyal service. These misguided trolls therefore guard Hakkar and his minions with reckless fervor.