After Tarron was colonised, the Vorassan cult came into existence and began converting the colonists and killing those who refused. The Kephrans stopped the cult, and created the Azmec Corporation to run the now chaotic colony, faking a holovid that control had officially been turned over to them.
Centuries later, the Kephra saw that the Tarronians were developing technology that would reveal the holovid was a fake. To prevent this, they used a primitive Time Scoop to kidnap the founder of the Vorassan cult, Akha Vorass, and have him kill the top scientists in the field. They also developed holoprobes of their own and denied all requests to reconstruct the old holovids. The First Doctor and Dodo investigated and found the faked holovids. The Kephra were banished from Tarron and the Tarronian civilisation devolved into anarchy. (PROSE: Tarnished Image)