The Dnyarri Slave Empire (20,000 BCE to about 17,500 BCE) Was a Ancient Alien species Space country that formerly existed in what the Earthlings called the Pre-historic times. This Space country was mainly located on the boundary between the local quadrant and what Star Trek calls the Gamma Quadrant. The space region is billions of stars mostly dwarfs but controlled 1/16th or more of the entire Milky way at one time although this 1/16 was never fully developed like Earthling space was which was 1/100th if the entire Milky way galaxy. By comparison Contemporary Chmmr space controls about 5% (Including the Neutral Zone shared with the Earthlings) of the entire Galaxy but its still the largest Space Empire currently in the 2160s CE. But 1/16th is closer to a whooping 6.7% of the Galaxy. But to be Fair the Dnyarri Slave Empire was spread out over 30% of the Galaxy but due to its developing economy status it was always as if they only controled 6.7% of the Galaxy. It remains unclear if the Dnyarri Empire had knowledge of the Earthlings. But it is known that Dnyarri space did include the Vulpeculae constellation where the Taalo lived.
Then as now, the primary mystery most sentient species sought to investigate was the disappearance of the Precursors. The Ur-Quan scouts were a new and invaluable asset in searching for Precursor artifacts. One Ur-Quan scout discovered a planet, later known as Glilandy, that showed readings particularly reminiscent of Precursor artifacts. Unfortunately, those readings turned out to be generated by the emanations of an incredibly powerful race of psychic sentients known as the Dnyarri. Ur-Quan minds are particularly susceptible to psychic manipulation, and at the very moment the Ur-Quan scout landed on the planet, his mind was seized by the Dnyarri and examined. Learning of the immense wealth of resources and labor to be had in the Sentient Milieu, the Dnyarri forced the Ur-Quan to return to the Milieu capital planet with hundreds of Dnyarri as cargo, and within a month the Dnyarri had seized control of all Milieu races and spread themselves throughout the Milieu, using the industry of a hundred worlds for their own vulgar amusements.
The Taalo were immune to Dnyarri control; thus, they had to resort to brute force for dealing with them. The Dnyarri compelled the other Milieu races to raze the Taalo homeworld. The Taalo did not fight back (though it is possible that they fled to *Pretty Space*). To this day, the Ur-Quan still feel guilty for this barbarous act, even though they were under mental control and had no choice. The easily compelled Ur-Quan were the favored slaves of the Dnyarri, and the agents of the extermination of several races deemed "worthless" due to their inefficiency and lack of speed, such as the Drall and the Yuli.
As time went on, the Dnyarri decided to use the Ur-Quan's own science to genetically engineer the Ur-Quan into physically distinct subspecies or castes to perform certain tasks. One group of Ur-Quan were optimized for intellectual tasks, performing scientific and engineering research to improve the Slave Empire's infrastructure and conducting administration and management on the Dnyarri's behalf. The other Ur-Quan, meant to serve as manual laborers and soldiers, were optimized for strength and diligence in performing manual tasks. The brown exterior of the Ur-Quan originally disappeared in these genetic alterations, leaving the administrative Ur-Quan with a green skin, and the workers with a black skin.