The monk was meddling in history to change it for what he considered to be the better: lending mechanical assistance to the builders of Stonehenge; giving Leonardo da Vinci tips on aircraft design; making money by using time travel to exploit compound interest; and, when the Doctor first encountered him, attempting to prevent the Norman Conquest as part of a plan to guide England into an early age of technological prosperity.[4] On that occasion he wore the guise of a monk in order to gain the trust of the 11th-century locals of Northumbria, hence the name by which he became known within this serial.[2] The Doctor stranded the monk in the 11th century by stealing his TARDIS's dimensional controller, which reduced the interior dimensions of the time machine to minuscule size.[4]
