In the twelfth century, a mysterious letter began to circulate around Europe. It told of a magical kingdom in the East that was in danger of being overrun by infidels and barbarians. This letter was supposedly written by a king known as Prester John.
Throughout the Middle Ages, the legend of Prester John sparked geographic exploration across Asia and Africa. The letter first surfaced in Europe as early as the 1160s, claiming to be from Prester (a corrupted form of the word Presbyter or Priest) John. There were over one-hundred different versions of the letter published over the following few centuries. Most often, the letter was addressed to Emanuel I, the Byzantine Emperor of Rome, though other editions were also often addressed to the Pope or the King of France.
The letters said that Prester John ruled a huge Christian kingdom in the East, comprising the "three Indias." His letters told of his crime-free and vice-free peaceful kingdom, where "honey flows in our land and milk everywhere abounds." (Kimble, 130) Prester John also "wrote" that he was besieged by infidels and barbarians and he needed the help of Christian European armies. In 1177, Pope Alexander III sent his friend Master Philip to find Prester John; he never did.
Despite that failed reconnaissance, countless explorations had the goal of reaching and rescuing Prester John's kingdom that had rivers filled with gold and was the home of the Fountain of Youth (his letters are the first recorded mention of such a fountain). By the fourteenth century, exploration had proved that Prester John's kingdom did not lie in Asia, so subsequent letters (published as a ten-page manuscript in several languages), wrote that the besieged kingdom was located in Abyssinia (present-day Ethiopia).
When the kingdom moved to Abyssinia after a 1340 edition of the letter, expeditions and voyages began to head to Africa to rescue the kingdom. Portugal sent expeditions to find Prester John throughout the fifteenth century. The legend lived on as cartographers continued to include the kingdom of Prester John on maps through the seventeenth century.
Throughout the centuries, the editions of the letter kept getting better and more interesting. They told of strange cultures that surrounded the kingdom and a "salamander" that lived in fire, which actually turned out to be the mineral substance asbestos. The letter could have been proven a forgery from the first edition of the letter, which copied exactly the description of the palace of Saint Thomas, the Apostle.
Though some scholars think that the basis for Prester John came from the great empire of Genghis Khan, others conclude it was merely a fantasy. Either way, Prester John profoundly affected the geographical knowledge of Europe by stimulating interest in foreign lands and sparking expeditions outside of Europe.
For More Information
Boorstin, Daniel J. The Discoverers.
Kimble, George H. T. Geography in the Middle Ages. Russell & Russell, 1968.
Wright, John Kirtland. The Geographical Lore of the Time of the Crusades. Dover Publications, Inc., 1965.