Luminus was a group who established themselves on many worlds.
They controlled all aspects of society wherever they ruled. Shortly after one planet, Olleril, was colonised, Luminus was apparently overthrown, but in fact they continued to rule the planet in secret. The cult was later taken over by Crispin, who plotted to establish his own version of perfect order on Olleril. He was defeated by the Seventh Doctor and the power of Luminus was broken. (PROSE: Tragedy Day)