1555

The Sixth Doctor and Evelyn Smythe visited England of January 1555, in pursuit of the source of a temporal nexus causing Smythe's family to disappear from the timestream. Posing as Queen Mary's physician, the Doctor discovered it was Smythe's own actions in encouraging an attempt on Mary's life that were paradoxically causing the nexus. Averting these attempts - after a spell in the Tower of London - the TARDIS occupants left England, with Mary praying for the Doctor to return and for the safe birth of an heir, neither of which came to pass. (BFA: The Marian Conspiracy)