Alternate timeline (The Eternity Clock)
The Eleventh Doctor and River Song visited an alternate timeline whilst collecting the pieces of the Eternity Clock. The last piece was found by the New Dalek Paradigm, who travelled back to 2106 and used it to lock London in a time bubble. They planned to expand the temporal field to swallow the entire planet, cutting it off from history. Once perfected, the Eternity Clock trap would allow the Daleks to freeze any planet that had ever existed, including Gallifrey. However, the Doctor and River Song confronted the Dalek Emperor and they reversed the polarity of the Dalek Matrix, deactivating the time lock, the Doctor being aware that "this little piece of rewritten history" would be "fixed", having never have happened. (GAME: The Eternity Clock) Human historians were aware that the Doctor and River were successful in recovering the Eternity Clock. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)