John Mandeville depicts the fictional land of Prester John in his Book of Marvels and Travels as somewhat utopic. He describes Prester John himself as an Emperor over all of the islands of India, overseeing the kings of seventy-two provinces, all whom have a number of other kings subject to them. The place where Prester John resides is called the isle of Pentoxoire, of which the greatest city is called Nisa. Mandeville emphasizes the wealth of this land, portraying it to be abundant with precious stones, including an entire river that is composed of gemstones instead of water, which flows out of paradise, through enormous mountains, and into a sea of sand which yields especially sweet-tasting fish. Prester John and most of his subjects are purportedly Christian. Though they do not possess “all the articles” of the faith extending from the organized Church authority of Western Europe, they believe in the Holy Trinity and practice the faith with great devotion. Mandeville lauds this fictional group of people as especially loyal, and caring not for material possessions.

Mandeville also describes the political nature of Prester John’s land. In addition to discussing how many kings are under his authority among the numerous islands of his so-called Empire, Mandeville builds up the mythology of this place by describing the composition of his court — kings, dukes, earls, bishops, and so on. He claiming that the Prester John always marries the Great Khan’s daughter and that the Great Khan always marries the Prester John’s daughter. This construction of a political relationship with an existing empire is interesting in its attempt to ground the land of Prester John in some reality. Some details of Prester John’s military forces and practices are also described. When he marches into battle against other rulers, he is accompanied by an army of “innumerable men” and gemstone-encrusted crosses are carried before him. This builds on the idealization of Prester John as a figure in the text: he is not only immensely faithful, but rich and noble and strong in battle as well.

Mandeville does not have much information to convey about the travel journey to the land of Prester John. He merely says that one can get there by travelling through Persia, and names a couple of cities one passes through along the way. Once one arrives at Pentoxoire, it takes a journey of four months to traverse it. He takes care to emphasize that the land of Prester John is incredibly remote and difficult to reach. He reports that, in addition to its remoteness, people from afar typically avoid going there because of the danger of sea travel. According to Mandeville, the presence of large adamantine rocks in the land of Prester John poses a particular threat to ships by pulling iron nails out of wood. These serve as convenient explanatory notes considering this land does not exist and Mandeville never travelled to any of the places in his Book of Marvels and Travels anyway.

Mandeville’s depiction of Prester John acts as a kind of assurance to Western European Christians: if one travels far enough past Jerusalem, one will reach Christianity again. This imaginary Christian empire on the other side of the world is presented as mystical, morally pure, and virtually unreachable, revealing the theological desires and uncertainties of the medieval European mind.