The Dark Templar
The dark templar are powerful psionic warriors whose forebears
were exiled from the protoss homeworld of Aiur over a thousand
years ago. The protoss who would eventually become the dark
templar were banished for their refusal to join the emerging
Khala, the communal mind link shared by all protoss, and the
accompanying caste system enforced by the ruling Conclave of the
protoss.
Some protoss rejected this movement, believing that their
individual identities would be erased to further the suffocating
rule of the Conclave. They even went so far as to sever the long
nerve tendrils that characterize the protoss. This act
symbolically and literally cut them off from the primal chord of
their race. The Conclave saw these rogues as a threat to the new
order and charged the Templar caste with hunting and destroying
them.
The Conclave was not willing to punish the templar openly for
their disobedience because doing so would reveal the existence
of the rebels. Instead, the dissident protoss were loaded aboard
an ancient but functional xel'naga vessel and launched into
space.
The exiled protoss wandered far before eventually making a new
home on the twilight world of Shakuras. They developed a
solitary and independent culture, with individuals often widely
scattered across space in their own ships, exploring and
contemplating the mysteries of the universe. Over time these
dark templar have learned to wield a very different kind of
psionic strength than that of the Khala: the energies of the
Void, the dark spaces between worlds.