La leggenda del Prete Gianni e lo spostamento degli orizzonti geografici (e culturali) d'Europa. A Erodoto a Ariosto

The legend of the Priest Gianni captivated Europe with the promise of a powerful Christian king in Asia, ready to aid the crusaders. Pope Innocent IV, during the Council of Lyon in 1245, gave the mendicant orders the task of exploring the East in search of this legendary ruler, but to no avail. The legend, born from a combination of scant geographical information and classical and biblical sources, became deeply rooted in the Eu- ropean imagination. The Priester John represented a ruler in possession of immense wealth and power, described in numerous chronicles and legends. The myth was consolidated with various tales, such as those reported by Otto of Freising and Hugo of Gabala, which told of a victorious Christian king over the Muslims. The spread of the legend was fueled by apocryphal letters attributed to Priest Gianni and by missions such as that of John of Pian del Carpine, who, although he did not find the legendary king, helped perpetuate the myth. Friar William of Rubruck, during his journey to Mongolian the early 1250s, also found no confirmation but helped demystify many Eastern legends. Marco Polo, in his accounts, mistakenly identified the Priester John with historical Asian figures such as the Wang Khan of the Kerait. Subse- quent voyages by John of Montecorvino and Rabban Sauma helped keep the legend alive, but with the transition to the 14th century and the end of the Crusades, the figure of the Priester John gradually lost its relevance, turning into a historical and literary myth rather than a concrete hope for an alliance against Islam.