The Fifth Doctor had resolved to take Peri Brown and Erimem to London in 1485 to investigate the historical mystery surrounding King Richard III of England and the princes he reportedly kept in the Tower of London. The Doctor's TARDIS accidentally materialised in 1483, when Peri and Erimem exited under instructions from the Doctor to meet him at the Kingmaker. The TARDIS then dematerialised and re-materialised at its target coordinates, two years later.
Stranded in 1483, Peri and Erimem were forced to work as serving wenches at the Kingmaker for two years, due to being, from their point of view, abandoned by the TARDIS in 1483. When the Doctor returned to the tavern in 1485, he learned of Peri and Erimem's plight, due to letters they had left with Clarrie. He also learned that they no longer worked there, as Clarrie had had to give his nieces Susan and Judith their jobs. Said nieces were in fact the long-lost children of King Edward IV of England, sent into hiding by their uncle (and Clarrie's brother) Richard III. (AUDIO: The Kingmaker)