Fall of Aiur

The Fall of Aiur was a pivotal event in the history of the protoss and the war between the protoss and the zerg.

Background
The Fall of Aiur followed the zerg invasion of Aiur, and occurred simultaneously with the Protoss Civil War. The war ended when high templar and former executor Tassadar destroyed the Overmind.

The Retreat
Aiur had been left a smoking ruin by the conflict. Meanwhile the zerg rampaged across Aiur, destroying 70% of the protoss population, including the Conclave.

Zeratul convinced Aldaris that the Khalai refugees should retreat to the last functional warp gate on Aiur and flee through it to Shakuras. Zeratul personally led troops to and through the gate, but hundreds of thousands of protoss were killed during the evacuation. Fenix and Jim Raynor volunteered to guard the Aiur side of the gate from the zerg. Large numbers of protoss fled over the course of three days, until Fenix and Raynor were forced to close the gate to prevent more zerg from forcing their way through it to Shakuras.

Abandonment
The remaining protoss who were stranded on Aiur scattered in a panic. One group, led by Fenix and Raynor, remained near the warp gate. Another group, which called itself the Shel'na Kryhas ("Those Who Endure"), led by the templar Ladranix, coalesced and sheltered in the ruined cities in Antioch. One of their first tasks was to destroy all flying zerg minions, a task made easier by disarray amongst the zerg, which included a lack of spawning.

The Shel'na Kryhas eventually lost many members to a splinter group, called the Tal'darim ("The Forged"), led by Felanis. The Tal'darim took shelter in the caverns beneath Aiur which had been forbidden thousands of years ago by the Conclave. There they worshiped a mysterious "Benefactor" they called the "Xava'tor". They were controlled by a drug known as Sundrop. The Tal'darim learned to capture zerg, and seemed to suffer fewer losses to the zerg than the Shel'na Kryhas, leading many former Shel'na Kryhas to defect to the Tal'darim.

Four years after the abandonment of Aiur, only "hundreds" of Shel'na Kryhas, including only three templar, remained.

The Escape
A trio of travelers approached Aiur, seeking an artifact for reasons which were mysterious to two of them. They were Jake Ramsey, a terran archaeologist and Rosemary Dahl, a former mercenary and assassin, fleeing from the Terran Dominion's Heir Apparent, Valerian Mengsk. Ramsey contained within his brain the spirit of the protoss preserver Zamara, who held a dark secret she desperately wished to bring to her people.

The group were surprised by the large numbers of zerg present on the world, but were rescued by the Shel'na Kryhas. The two groups joined forces.

Zamara needed to acquire the artifact to rescue Ramsey from the tumor her presence was forming in his brain. She did not immediately inform Ramsey of this, however. She arranged for Dahl to sneak into the Tal'darim caverns and see what the defenses were, but she was captured by Felanis and his former templar henchman, Alzadar. They subjected her to Sundrop, which was addictive to terrans as well as protoss. Dahl was eventually reunited with Ramsey and Zamara, and eventually they were able to break her addiction. From her subconscious, they discovered much of the truth behind the Tal'darim -- they were, in fact, being controlled by the powerful dark archon Ulrezaj.