The Trial of a Time Lord 13-14 (aka The Ultimate Foe) - S23-E4
Factual error: The Master states that Earth and its entire constellation were moved, but constellations are merely patterns of stars (as viewed from a given point, like Earth) that may be nowhere near each other - the Earth could not really be described as being in a constellation as any sort of specific entity that could be moved.
Answer: TARDISes are generally available for properly authorised use on Gallifrey; they're not usually assigned to a particular Timelord on a long-term basis. The Doctor stole his when he left his homeworld.
Tailkinker ★