Protoss are the more empathic alien species from the computer game Starcraft. They have an average height of nearly nine feet, towering over the Terrans of the Koprolu sector, and are characterized by digitigrade legs, hands with four digits (two of which are opposable), the lack of a mouth, and long cords of nervous tissue1 behind a crest at the top of their head. They have an instinctive use of psionics, and the bundles of nerve cords link them into a telepathic communications link with the rest of the Protoss.
Protoss (meaning 'the First Born') were the creations of the Xel'Naga. The Xel'Naga were a race of aliens who spread throughout the galaxy millions of years ago, altering the evolutionary paths of lesser species in the hopes of creating a race of perfect beings. The Protoss were their most successful attempt yet, imbued with a purity of form2. The Xel'Naga observed the Protoss from orbit for millennia, and came down when they believed that their creations were ready for them.
The Protoss, sadly, were not. Since their creation, they had subtly drifted away from their roots. They had clustered into tribes, and were gradually losing even their telepathic link with the rest of their people. The Xel'Naga, disappointed in their failed project, prepared to leave the planet of Aiur to begin again somewhere else. The Protoss, enraged at being abandoned by the beings who had recently been worshipped as gods, launched hasty attacks against the Xel'Naga that remained on the surface. The Xel'Naga were caught off guard, but quickly drove off the Protoss and launched their ships back into space. Left without the most convenient object to project their anger at, the Protoss descended into an immeasurably long civil war known as the Aeon of Strife.
The Aeon of Strife was brought to an end largely due to a Protoss known as Khas. Khas had studied what the ancient Xel'Naga had left behind, now millennia old. During his studies, he unearthed the massive Khaydarin crystals that the Xel'Naga had used to channel the psionic energies of the Protoss. Using the crystals, Khas was able to access the racial link that his ancestors had lost. He created an almost religious path of progression to mastering the powers that the ancient Protoss had allowed to atrophy, and called it the Khala. It led the Protoss to regain the glory that had been lost ages ago.
The Khala redefined Protoss government, switching it from a warring assembly of tribes to a unified, caste-based system. Under the new rule, tribes were merely a mark of common ancestry, and had little bearing on their place in society--although certain tribes often produced children with a well-defined talent for certain occupations that their ancestral tribesman had excelled at. The Judicator caste formed the new Protoss government, a group of almost-sovereign leaders ruled over by a group of elders known as the Conclave. The Khalai are the second caste, made up of the scientists and workers who keep the Protoss society moving. Finally are the Templar, the warriors and defenders of Aiur. Soon the Protoss had spread far beyond their home system, and under the Khala's guidance, had accepted the stewardship of Dae'Uhl, and protected the races inhabiting the areas they found.
Even as Protoss spread away from Aiur and into the galaxy, the Conclave hid secrets from the common pepole. Hidden on the plains of Aiur were a few remaining tribes who believed that submitting to the Khala would erase their identities to further the Judicators' rule. The Conclave sent a group of Templari warriors led by Adun to bring the rogue tribes 'to the light'. Adun believed that the tribes could be convined of the Khala's truth by teaching them to control their psionic abilities. This, however, led only to undisciplined Protoss wielding powers greater than they could control. Horrified that the rogues had not been wiped out, the Conclave banished the 'Dark Templar' to space in an ancient Xel'Naga vessel.3 Adun and the other Templar were sworn to secrecy, and the Conclave again covered up the existence of the individualistic tribes.
The Protoss spread, now with no conflict from within remaining, and acted with the Dae'Uhl to protect the races they found, until the arrival of the Terrans. The Koprolu Terrans, all exiles from Earth and occupied human space, sped from world to world, stripping their resources to regain the technology they lost when they were cast away from Earth. While the Protoss were attempting to deal with humanity without violating the Dae'Uhl, they found the first scouts of the oncoming Zerg, the final creation of the Xel'Naga. They sent the Templar Tassadar4, leading a small fleet of warships, to examine the new Terran space. They were horrified to learn that some of the human worlds, Chau Sara, had already become nesting grounds for the Zerg, and the Conclave hurriedly ordered Tassadar to bombard the surface of the planet until the Zerg prescence was eradicated. Tassadar, wracked with guilt over the human losses on Chau Sara, defied the order to destroy nearby Mar Sara, seeking instead a way to defeat the Zerg without the destruction of humanity and the ecologies of the planets the Zerg held...
1- These nerve cords are only long in Protoss who follow the Khala, as the
Dark Templar ritually cut them short.
2- After the Protoss, the Xel'Naga created the
Zerg, imbued with
purity of essence, and were later destroyed by them.
3- Adun has become a household name through the greeting '
En Taro Adun', in memory of his attempts to save the Dark Templar.
4- Similarly, Tassadar's actions during the plot of
Starcraft lead to greetings of '
En Taro Tassadar' in the expansion,
Brood War.
Protoss are copyright Blizzard, not me. Above information stolen (blatantly) from the pages of backstory in the Starcraft manual. I take no credit, but I would take a few upvotes.