- A protoss battlecry(src)
A great psionic matrix emanated from Aiur. Protoss structures and units, to a lesser extent, drew their energy from it. A nexus provided a link to this matrix, but pylons were needed to actually tap into the energy required to provide psionic energy to new colonies.
Aiur possesses great, almost spiritual significance to all Protoss.
Aiur's moderate greenhouse-gas levels and low orbital eccentricity allowed it to develop a climate conducive to life. 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. In addition to digging vast subterranean caverns, the xel'naga constructed a temple to mark the site where they first set foot upon Aiur.
The xel'naga eventually left Aiur due to growing antagonism among the protoss that led them to forget how to attune themselves to their primal psychic link. This led to the Aeon of Strife, during which Aiur's greater landmasses were devastated and many of its lesser life-forms were pushed to the brink of extinction.
Eventually, Khas unearthed khaydarin crystals left behind by the xel'naga. He channeled their primal energies through himself and rediscovered the communal psionic bond of the protoss. Khas revitalized protoss society through the Khala, which called upon the them to forgo their old feuds and reunite. Gradually, the protoss embraced their psychic link and were flooded with the thoughts, emotions, and experiences felt by every protoss.
The following centuries 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 few rogue tribes rejected the Khala. The Conclave ordered the Templar Caste to eradicate them, but instead Adun attempted to convince the rogues of the Khala's truth by teaching them how to manipulate their own latent psionic powers. Without the Khala's discipline, however, their powers spiraled out of control and unleashed psionic storms across Aiur. The Conclave banished the rogue tribes from Aiur.
In 2500, the zerg launched a full-scale invasion of Aiur. The protoss defenders were overrun and countless zerg carved swaths of destruction across Aiur's continents. They seized the khaydarin crystals and destroyed the xel'naga temple before setting the khaydarin crystal in its place, allowing the Overmind to embed itself in Aiur's surface.
When former Executor Tassadar, a veteran of previous battles of the zerg who had turned rebel, returned to Aiur with Dark Prelate Zeratul, Judicator Aldaris attempted to arrest them. Tassadar's followers destroyed Kor-shakal.
With the help of the renegade terrans of Raynor's Raiders, Tassadar and his followers weakened the Overmind, sustaining heavy losses in the process. Tassadar channeled Dark Templar energies through the hull of the Gantrithor and steered it on a collision course with the Overmind, destroying it. However, the zerg invasion left much of Aiur in ruins. The Conclave and nearly seventy percent of the population was killed. Aldaris, Fenix, Zeratul and Commander Jim Raynor banded together in order to unite and lead the scattered survivors, but the zerg continued to slaughter every protoss they encountered.
The Brood War
At Zeratul's suggestion, the Khalai survivors retreated to their last functional warp gate, fighting through a sizable zerg force to get there. Fenix and Raynor held back and protected their flank while the Khalai survivors escaped to Shakuras. Hundreds of thousands of protoss died during the evacuation. Some protoss were stranded on Aiur, and some observers remained behind to keep watch.
The zerg took control of the gate, but Raynor and Fenix retook it and shut it down to prevent the zerg from sending more reinforcements to Shakuras. Praetor Artanis sent though all the troops he could spare.
After being contacted by Sarah Kerrigan, Raynor brought Emperor Arcturus Mengsk, fleeing from the United Earth Directorate, to Aiur. The warp gate was activated and Fenix's troops held off the zerg who were incited to attack by its energies. Raynor's command center was destroyed by UED troops, but Lieutenant Samir Duran, supposedly a UED colonial officer, moved his forces out of place and the zerg intervened, allowing Mengsk and Raynor to escape through the warp gate while the UED retreated.
The protoss refugees on Shakuras made at least one trip to Aiur to recover wounded protoss warriors. Protoss commanders noticed stranded protoss but, believing they could not be rescued, kept their existence secret. The resurgent motherships would return to Aiur briefly and evacuate what groups of survivors they could, but upon their departure, Aiur belonged to the zerg, and the remaining survivors were stranded.
Around 2503, the zerg occupiers had stopped fighting each other, but had stopped spawning and continued to wander the planet like "discarded tools."
The stranded protoss divided into two factions—Shel'na Kryhas and Tal'darim—and clung to life on the ruined world, fighting and avoiding conflict with the zerg. The arrival of a preserver, contained within the brain of terran archaeologist Jake Ramsey, brought great changes to both groups of protoss. The former attempted to flee through the disabled (and then repaired) Warp Gate, while the latter splintered as they learned the truth behind their mysterious Benefactor. The Shel'na Kryhas and renegade Tal'darim banded together to attack the Benefactor, most giving up their lives using a powerful psionic technique to hold the Benefactor off.
Some of the renegade Tal'darim escaped but none of the Shel'na Kryhas made it. The remaining Tal'darim were attacked by zerg forces led by Ethan Stewart, who was seeking to use the gate and then find Ulrezaj. Ulrezaj absorbed some of his own followers to recharge his power before leaving in a xel'naga vessel, pursued by the zerg and Dominion.
Aiur came under Kerrigan's control. Although some areas were left untouched by the invasion, much of Aiur became a zerg breeding ground littered with ash, broken war machines, and the remains of the dead. A small number of protoss speculated that some of Aiur's other life-forms had been assimilated by the zerg and mutated into killing machines to serve the Swarm.
Some Khalai, outraged over the fall of Aiur, returned to the planet and waged a guerrilla war against the zerg. These Avenger adopted the tactics of the Nerazim and utilized warp technology to for quick escapes.
This article or section contains information about StarCraft: Ghost, which has been declared non-canon. Elements may be taken as 'flavor lore' however.
Echoes of the Future
In 2504, Zeratul returned to Aiur to learn the Overmind's secrets by making contact with the tendrils connected directly to its cortex. There he encountered the spirit of Tassadar, who revealed that the directive to destroy the protoss was forced upon the zerg and that Kerrigan was the only one who could free the zerg from slavery.
In 2506, a small band of warriors established a beachhead within the ruins on Aiur's surface. The protoss freed the warp conduits at Kherrisan of infestation. In the process, they discovered that the zerg on Aiur were being led by hybrid. Once the warp network was secured, protoss starfighters moved to take the fight across the surface of Aiur. Artanis had Executor Selendis take command of the invasion while he and Zeratul discussed the most recent turn of events further on the battlefield.
Amon corrupted the Khala. Zeratul severed Artanis' nerve cords, at the cost of his own life. Artanis rescued Phase-smith Karax, whose nerve cords had been removed by a Nerazim. They went to the ruins of Kor-shakal to reactivate the Spear of Adun. The power cells were cleared of creep, at which point Karax warped all protoss freed from Amon aboard the Spear of Adun, then departed Aiur.
Amon forged a host body with the flesh of the possessed protoss and the Overmind's carcass.
"Then we shall build a better one on top of it!"
- Artanis and Fenix(src)
To prevent Amon from bringing the Golden Armada down upon them, Artanis planned to dismantle the psi matrix. Matriarch Vorazun and Highlord Alarak purged Antioch of the zerg and destroyed the power structure in the Citadel of the Executor. Karax and Fenix destroyed the power structure on the temple grounds, releasing a massive overflow of psionic energy from the surface of Aiur. Artanis and his warriors kept ahead of the energy storm and slayed the zerg in the xel'naga caverns with the help of the Tal'darim, Purifiers and Nerazim. Once the final power structure fell, Rohana had them recalled.
Amon's host body was fed by Void shards that drained life around them and destabilized the land near them as Amon terraformed the area into the Void. Artanis had his warriors destroy the shards. It was then that Amon's form awakened, but it was destroyed by a massive orbital bombardment.
The Keystone was placed in a temple. While it charged to its full power, Vorazun and the Nerazim held the northern entrance, Karax and the Purifiers secured the southern approach and Alarak laid claim to the primary battle line. Artanis' forces ensured the Keystone's safety and provided for their defense. Amon laid siege from all directions, first sending his zerg, then the possessed Templar. Once it was ready, Artanis had his warriors pull back to it. The Keystone extracted Amon from the Khala. Artanis convinced Selendis and the Templar to sever their nerve cords, thrusting Amon back into the Void. The Daelaam began rebuilding Aiur's cities.
Aiur is a planet high in biodiversity and has a large variety of flora and fauna. Known species include;
- Crab beetle
- At least one species of bird
- Various aquatic species about the size of leeches.
- Aldera (destroyed)
- Kherrisan (destroyed)
- Khor-shakal (fortress city, destroyed)
- Mendella (ruins, replaced by a proving ground)
- Brushfire Island
- Cave of Relics
- Eldritch Lake
- Middling Peaks
- Gantrimoss Crater
- Garden of Aiur
- River of Light
- Road of Remembrance
- Shreka Hills
- In the StarCraft II map editor, there exists a map of Aiur, showing the spread of creep across its surface. However, apart from the creep spread, this map is identical to one of Bel'Shir, so assessing its validity is difficult.
- The planet appears as a contestable territory in RISK: StarCraft.
- Aiur is erroneously shown to have three moons in the ending cinematic for the main Legacy of the Void campaign. Artist David Loung stated that the planets were the same three planet from the StarCraft: Brood War cinematic "Fury of the Xel'Naga," however that cinematic took place on Shakuras rather than Aiur.
- Aiur was to feature as the third level in early builds of StarCraft: Ghost. Jackson Hauler sent forces to mine terrazine from the world, but would be forced back by Khalai forces. Nova would have to drive back the protoss from his operation, fighting various protoss forces (including an arbiter), but would then be betrayed by Hauler.