Cloister Wars

The Cloister Wars were a series of conflicts mentioned by to Clara Oswald when explaining how long she had cared for the Doctor. She also mentioned "the night he stole the moon and the President's wife", and that it had also been so long it was "since he was a little girl". She then asked if Clara could tell which statement was a lie. (TV: The Magician's Apprentice) While in the Cloister, the Twelfth Doctor encountered a trapped Dalek and he hinted it could be there since the Cloister Wars. (TV: Hell Bent)