The International Prester John Project: How A Global Legend Was Created Across Six Centuries

Histoire de Genghizcan

In 1710 François Pétis de la Croix (1653-1713) published a widely influential biography of Genghis Khan that was written by his father and edited by François himself. 

In it, the de la Croix's speculate that the Letter of Prester John was a forgery perpetuated by Nestorians in Asia but also argue that the patriarch himself is a real, historical personage.