For Prester John see Sir Henry Yule's article 'Prester John' in the _Encyclopaedia Britannica_, and Lynn Thorndike, _A History of Magic and Experimental Science_ (1923), II, pp.

236-45.

There is a pleasant popular account in S.Baring Gould, _Popular Myths of the Middle Ages_ (1866-8).
15.

For their accounts see _The Journal of William of Rubruck to the Eastern Parts, 1253-5, by himself, with two accounts of the Earlier Journey of John of Pian da Carpine_, trans.

and ed.