Kings of Space

The Kings of Space were two "God units" located on a planet in the centre of Sphinx-space. Like all the other Gods, their true nature and agenda was a matter of much speculation in the rest of the universe.

Nature
Each of the Kings of Space covered an entire hemisphere of the planet, and they were the mother and father of all sphinxes. According to Professor Begarius, one of the Kings was "as dark as a black hole" and the other was "as bright as a supernova." With their large sizes, the Kings of Space could create whole worlds with little effort. They created the Sphinxes, artificial beings with no individuality, who had the ability to physically create more space for them to rule over. As a result, they had no need to take over more of the existing universe, merely expanding Sphinx-space around themselves. Christine Summerfield speculated in Dead Romance that, since the sphinxes were like computers or computer programs, the Kings of Space were the central databank. (PROSE: Dead Romance)

History
The Homeworld understood the Kings of Space to stand apart from the main group of "Gods" whom they had quarrel with, believing the Kings to be "renegades" among their own kind, although still of the same fundamental nature as the other Gods. The identity of the Gods was itself a fraught subject, including such guesses as that the Gods had been part of the universe since its inception; (PROSE: Dead Romance) that they were the Time Lords of a universe "above" Cwej's who were fleeing from a war that could wipe them out into a bottle in much the same way that Cwej's employers were fleeing from the Gods into a further bottle; (PROSE: Dead Romance, Interference) or that, whatever the identity of the Kings of Space, the "All-High Gods" who took over Dellah were in actual fact Ferutu, (PROSE: Twilight of the Gods) a race from a parallel universe who, in their timeline, supplanted the Time Lords as the rulers of their Web of Time, and manipulated time using methods more obviously akin to magic than the Time Lords', using runes. (PROSE: Cold Fusion) In yet other accounts, after a flotilla of War TARDISes became stranded in the ancient past on a deserted planet, retaining their dimensional transcendentalism and their intelligence but not the capacity for time travel, set up "an information network that spanned the entire world". (PROSE: The Taking of Planet 5, The Book of the War)

Despite their comparable peacefulness, they were fiercely territorial, and it was said that no one from the outside universe had ever come back alive from Sphinx-space.

The two "rogue Gods" had worshippers, who created a bottle universe using the Kings' techniques, as an offering to their Gods. However, this bottle was stolen by a renegade of the Homeworld's kind. In Chris Cwej's telling, this was a mad scientist who called himself "the Evil Renegade", because Cwej's new "employers" had altered his memories so he would have no lingering fondness for the true identity of the Homeworlder he previously travelled with, (PROSE: Dead Romance) the Doctor. (PROSE: Original Sin, etc.) Indeed, the Seventh Doctor carried at least one bottle universe in his TARDIS for some time coinciding with his travels with Cwej. (PROSE: Christmas on a Rational Planet) The bottle was stolen by the main body of the Great Houses, as they had developed a plan to colonise the Earth inside the bottle universe and turn it into a cloneworld where they could hide from the other Gods who actually threatened them in their home universe.

Learning that the bottle had passed into the Houses' hands, the Kings of Space sent a number of their sphinxes to Simia KK98 to collect it from the Houses' fortress there. However, Cwej managed to get the sphinxes to listen to him and call off their attack. He brokered an agreement whereby the Kings of Space would get access to knowledge of refined time travel techniques in exchange for allowing the Great Houses to "rent" the bottle Earth from them. A treaty was signed via a sphinx, and the botle Earth was indeed taken taken over and "terraformed" into a duplicate of the Homeworld. (PROSE: Dead Romance)

The Book of the War seemed to assign the same role in events relative to Chris Cwej and the early War era to "the Enemy" that Christine's memoirs in Dead Romance did to the orthodoxy of Gods to whom the Kings were supposedly renegades, and whom the Houses feared. (PROSE: The Book of the War, Dead Romance) However, Christine's understanding of the reputation of Sphinx-space as a place no one came back from alive (PROSE: Dead Romance) also directly paralleled the events of the Faraway mission and Head of the Presidency incident, which constituted the Houses' first official contact with the Enemy. (PROSE: The Book of the War)

Behind the scenes
Simon Bucher-Jones confirmed to Nate Bumber that the fate of The Taking of Planet 5 's war TARDISes that is described in The Book of the War was intended as a possible origin of the Kings of Space.