Aiur

Aiur was the homeworld of the protoss, a world on the galaxy's fringe orbiting a single yellow star and possessing a single moon. It was engineered by the Xel'Naga, who accelerated the evolution of the protoss and built a temple to mark the site where they first set foot upon it. For millennia Aiur was the hub of the Protoss Empire and held a deep significance for the protoss, who drew their strength from the great psionic matrix that emanated from the planet. Its golden age ended in 2500 when the zerg launched a full-scale invasion, and the world remained in zerg hands until it was reclaimed during the campaign against Amon. (StarCraft (manual); StarCraft: The Dark Templar Saga: Firstborn; StarCraft II: Legacy of the Void)

Origins and the Aeon of Strife#

Aiur was engineered by the Xel'Naga. Its moderate greenhouse-gas levels and low orbital eccentricity gave it a climate conducive to life, and over the eons its humid rainforests teemed with a variety of species, the most advanced of which were the protoss, whose evolution was accelerated by Amon and his followers. The Xel'Naga dug vast subterranean caverns beneath the surface and raised a temple to mark the site of their arrival. (StarCraft (manual); Koprulu Sector Systems: Aiur; StarCraft II: Legacy of the Void; StarCraft)

The Xel'Naga eventually left Aiur as antagonism grew among the protoss, who forgot how to attune themselves to their primal psychic link. The result was the Aeon of Strife, a long age of internecine conflict during which Aiur's greater landmasses were devastated and many of its lesser life-forms were pushed to the brink of extinction. The strife ended only when Khas unearthed khaydarin crystals left behind by the Xel'Naga, channeled their primal energies through himself, and rediscovered the communal psionic bond of the protoss. The Khala that Khas founded called upon the protoss to forgo their old feuds and reunite, flooding each protoss with the thoughts, emotions, and experiences of every other. (StarCraft (manual); Koprulu Sector Systems: Aiur)

The golden age#

The centuries that followed saw a golden age on Aiur. Its war-torn continents were healed, its native species flourished, and five cities and thirty-eight temples were erected across its surface. The protoss population swelled to billions, and Aiur became the hub of the Protoss Empire. A lattice of khaydarin crystals was embedded in Aiur's crust at the Citadel of the Executor, joining a temple and the Xel'Naga caverns to form the psionic matrix, which was sparked in 500 B.C.E. (Koprulu Sector Systems: Aiur; StarCraft II: Legacy of the Void)

Not all protoss accepted the Khala. A few rogue tribes rejected it, and the Conclave ordered the Templar Caste to eradicate them. Adun instead attempted to convince the rogues of the Khala's truth by teaching them how to manipulate their own latent psionic powers, but without the Khala's discipline their powers spiraled out of control and unleashed psionic storms across Aiur. The Conclave banished the rogue tribes from the world, and from them descended the Dark Templar who would settle on Shakuras. (StarCraft (manual); StarCraft: Brood War)

The fall#

In 2500 the zerg launched a full-scale invasion of Aiur. The defenders were overrun as countless zerg carved swaths of destruction across the continents. The Swarm seized the khaydarin crystals, destroyed the Xel'Naga temple, and set its own crystal in place, allowing the Overmind to embed itself in Aiur's surface. Praetor Fenix fought against the zerg but was hampered by the cerebrates' ability to reincarnate and held back by the incompetent leadership of the Conclave. (Koprulu Sector Systems: Aiur; StarCraft)

When the former Executor Tassadar, a veteran of earlier battles against the zerg who had turned rebel, returned to Aiur with Dark Prelate Zeratul, Judicator Aldaris attempted to arrest them. With the help of the renegade terrans of Raynor's Raiders, Tassadar and his followers weakened the Overmind at heavy cost. Tassadar then channeled Dark Templar energies through the hull of the Gantrithor and steered it on a collision course with the Overmind, destroying it. The invasion left much of Aiur in ruins; the Conclave and nearly seventy percent of the population were killed. At Zeratul's suggestion the Khalai survivors retreated to the last functional warp gate and escaped to Shakuras, while hundreds of thousands died in the evacuation and some protoss were stranded behind. (StarCraft; StarCraft: Brood War (manual); StarCraft: Brood War; StarCraft: The Dark Templar Saga: Shadow Hunters)

The zerg occupation#

After the Overmind's death Aiur came under the control of Sarah Kerrigan. Much of the world became a zerg breeding ground littered with ash, broken war machines, and the dead, though some areas were left untouched. The stranded protoss divided into factions, the Shel'na Kryhas and the renegade Tal'darim, and clung to life on the ruined world, fighting or avoiding the zerg. The arrival of a preserver contained within the brain of the terran archaeologist Jake Ramsey brought great changes to both groups before most gave their lives to hold off a mysterious Benefactor. (Koprulu Sector Systems: Aiur; StarCraft: The Dark Templar Saga: Shadow Hunters)

In 2504 Zeratul returned to Aiur to learn the Overmind's secrets by making contact with the tendrils connected to its cortex. There he encountered the spirit of Tassadar, who revealed that the directive to destroy the protoss had been forced upon the zerg and that Kerrigan was the only one who could free the Swarm from slavery. (StarCraft II: Wings of Liberty)

Reclamation and the war against Amon#

In 2506 a small band of warriors established a beachhead within the ruins, freeing the warp conduits at Kherrisan of infestation and discovering that the zerg on Aiur were being led by hybrid. Artanis had Executor Selendis take command of the invasion. Amon then corrupted the Khala itself, and Zeratul severed Artanis' nerve cords to free him from the corruption at the cost of his own life. Artanis rescued Phase-smith Karax and reactivated the Spear of Adun at the ruins of Kor-shakal, warping all freed protoss aboard before the vessel departed. Amon forged a host body from the flesh of the possessed protoss and the Overmind's carcass. (StarCraft II: Legacy of the Void)

To deny Amon the Golden Armada, Artanis dismantled the psionic matrix, with Matriarch Vorazun, Highlord Alarak, Karax, and Fenix destroying the power structures across the surface and releasing a massive overflow of psionic energy. Amon's awakened host body was destroyed by a massive orbital bombardment. The Keystone was then placed in a temple and charged while Artanis' allies held the approaches against Amon's zerg and possessed Templar. Once ready, the Keystone extracted Amon from the Khala, and Artanis convinced Selendis and the Templar to sever their nerve cords, thrusting Amon back into the Void. With the threat ended, the Daelaam began rebuilding Aiur's cities. (StarCraft II: Legacy of the Void)