The Pasharti are the result of genetic experiments performed by the Jeferi on semi-sapient lifeforms on their homeworld of Taralon. The purpose of these experiments was to create a subservient slave race, but the uplifting procedure worked too well.
The Pasharti not only achieved sapience, but also demonstrated the ability to convert other lifeforms into new Pasharti. Despite the Jeferi's attempt to stop the experiment, many Pasharti escaped into the wilderness. For many years, they hid from the Jeferi, stealing technology and abducting civilians to be converted into more of themselves. By the time the Jeferi discovered the Pasharti, they had already amassed the numbers and technology base necessary to rival them. Soon, the Pasharti seized control of Taralon and enslaved their creators, using them for personal servitude and breeding stock.
Once the Pasharti developed space travel, they recognised the possibility of other sapient life beyond their homeworld, and decided it was their solemn duty to assimilate all life in the galaxy into their empire.