Nerazim

A Dark Templar is a member of a group of Protoss. They cut off their psionic appendages to demonstrate their contempt for the Khala.

History
The Dark Templar were originally a group of Rogue Tribes which lived in hiding on Aiur. They were considered rogues for refusing to submit to the Khala. The Protoss Conclave knew of their existence, but had kept them a secret until about 1000 years before StarCraft starts. Fearing that the knowledge of their rogue nature would undermine their efforts of spreading the Khala, they determined that the Rogue Tribes were a threat, and ordered Adun to destroy them.



Adun was considered a very valiant and powerful young warrior. He was also an extreme idealist, so many Conclave members thought it was a mistake of the Judicators to send him.

Instead of destroying the Rogue Tribes, Adun tried to teach them psionics. One of the first abilities they learned was how to bend light around themselves, which renders them virtually invisible. He did this so the Rogue Tribes could hide from the Conclave.

He tried to teach them more powers, such as psionic storms, but this backfired. Without the discipline of the Khala they could not control these storms, which spiralled over Aiur.

Perhaps these storms were actually created by the first Dark Archons, as these psionic entities had not been created for 1000 years (about the time these storms took place) due to being too dangerous.

In any event, now the Protoss Conclave could not hide the existence of the Rogue Tribes, so now the Conclave had a choice to either destroy them, banish them or admit that they'd let them live. It is unknown what censure Adun received, but he probably continued to live for a time.

The barely reunited Protoss Tribes began to fight once more, in addition to the hunts called for on the Rogue Tribes. Eventually the Rogue Tribes were forced to surrender. Instead of destroying them, the Conclave had them loaded onto an old but functional Xel'Naga freighter and secretly exiled them. They became a taboo subject and the Judicators tried to hide the evidence. Over the years the stories emerged as rumors about Dark Templar and Fallen Ones.

The Rogue Templar journeyed through the stars for a long time, hundreds of years. During this time the creation of the Dark Archon was banned, and the habit of cutting off their psionic appendages became common. In order to use psionic powers, they were forced to draw energy from the void. They also developed their fleet of Corsairs, a vessels designed to defend themselves as they had travelled through the stars.

Zeratul, a Prelate of the Dark Templar, had said: "I have journeyed through the darkness between the most distant stars. I have beheld the births of negative-suns and borne witness to the entropy of entire realities..." Perhaps he was speaking of these journeys.

During these journeys the Rogue Tribes had encountered Char, probably early in their journey. While the Zerg had not yet reached Char, the Rogue Tribes somehow lost the Khalis crystal on the planet.

The Rogue Tribes eventually discovered the dark planet, Shakuras, during their journeys and remained, due to the presence of a Xel'Naga Temple.

On the planet, they either found or created a Warp Gate which they could use to travel to Aiur. However, they did not use that Gate to connect to Aiur for a long time.

Struggling to adapt to their harsh and nearly lightless environment, the Rogue Tribes altered their skills and even their biology to cope.

Eventually Matriarch Raszagal, age 1046 at the time of StarCraft: Brood War, and the only Dark Templar who was old enough to clearly remember Aiur, became the leader of the Dark Templar.

Dark Templar warriors are armed with modified Psi-Blade technology, known as warp blades, and strive to protect their race and the ancient secrets of their tribes. By channeling their dark energies through these blades, they can permanently kill Zerg Cerebrates.

After the devastation of Aiur, the Dark Templars forgave those Protoss who once banned them, and allowed their fellow brothers to escape to Shakuras.

Recently the Dark Templar have allowed the creation of the Dark Archon, which appears to be different and marginally more stable than its previous form.