Disciples of the Light

The Disciples of the Light were a highly advanced civilisation who, according to the Beast, lived before the universe the Doctor was native to was created.

History
Before the creation of the Universe, the Disciples battled with the Beast, and buried it on a planet later called Krop Tor. Both the planet and K37 Gem 5, the black hole it orbited, served as a prison for the Beast. (TV: The Satan Pit) Their means of maintaining the orbit without obvious technology surpassed even the Tenth Doctor's understanding. (TV: The Impossible Planet)