Etra Prime

Etra Prime was the oldest planet in the known universe.

History
The Daleks removed the planet from time and space so that they could mine the Apocalypse Element from the planet. Twenty years later the Daleks sent Etra Prime on a collision course with the planet Archetryx, which was hosting a temporal treaty attended by 20 membering races of the Temporal Powers. (BFA: The Apocalypse Element)