The legends of Prester John (also Presbyter Johannes) were popular in Europe from the 12th through the 17th centuries, and told of a Christian patriarch and king said to rule over a Christian nation lost amidst the Muslims and pagans in the Orient. Written accounts of this kingdom are variegated collections of medieval popular fantasy. Prester John was reportedly a descendant of one of the Three Magi, said to be a generous ruler and a virtuous man, presiding over a realm full of riches and strange creatures, in which the Patriarch of the Saint Thomas Christians resided. His kingdom contained such marvels as the Gates of Alexander and the Fountain of Youth, and even bordered the Earthly Paradise. Among his treasures was a mirror through which every province could be seen, the fabled original from which the "speculum literature" of the late Middle Ages and Renaissance was derived, in which the prince's realms were surveyed and his duties laid out.

John Buchan, 1st Baron Tweedsmuir PC GCMG GCVO CH (26 August 1875—11 February 1940) was a Scottish novelist, historian and Unionist politician who served as Governor General of Canada, the 16th since Canadian Confederation.