The Constructors of Destiny was an ancient race which evolved billions of years BC.
The Constructors of Destiny were considered gods and affected the development of the early universe and such worlds as Earth and Gallifrey. Eventually, the Constructors of Destiny developed a computer that was built into the very universe and could find out the ultimate truth. Despite the protests of a Time Lord from the future and the Xeraphin, the Constructors of Destiny created the Great Attractor. After it was turned on, its mind snapped and it annihilated the Constructors of Destiny. It built an army using Block Transfer Computations, who went out to gather the knowledge that could turn the Mad Mind into a god. The Mad Mind was also able to take over all the robotic races almost immediately.
The living races in the universe were forced to band together in order to defeat this army. This army, made of over a thousand fleets from as many planets, set out to try to stop the Mad Mind of Bophemeral, starting the Millennium War of 150 million BC, which ended with the defeat of the Mad Mind. One of the few remnants of the Constructors was the Midnight Cathedral on the dark side of the Moon. (PROSE: The Quantum Archangel)