Prester John - Letter of Prester John

No more of the tale is recorded until about 1165 when copies of what was certainly a forged Letter of Prester John started spreading throughout Europe. An epistolary wonder tale with parallels suggesting its author knew the Romance of Alexander and the above-mentioned Acts of Thomas, the Letter was supposedly written to the Byzantine Emperor Manuel I Comnenus (1143–1180) by Prester John, descendant of one of the Three Magi and King of India. The many marvels of richness and magic it contained captured the imagination of Europeans, and it was translated into numerous languages, including Hebrew. It circulated in ever more embellished form for centuries in manuscripts, a hundred examples of which still exist. The invention of printing perpetuated the letter's popularity in printed form; it was still current in popular culture during the period of European exploration. Part of the letter's essence was that a lost kingdom of Nestorian Christians still existed in the vastnesses of Central Asia.

The credence given to the reports was such that Pope Alexander III sent a letter to Prester John via his physician Philip on September 27, 1177. Of Philip, nothing more is recorded, but it is most probable he did not return with word from Prester John. The Letter continued to circulate, accruing more embellishments with each copy. In modern times textual analysis of the letter's variant Hebrew versions have suggested an origin among the Jews of northern Italy or Languedoc: several Italian words remained in the Hebrew texts. At any rate, the Letter's author was most likely a Westerner, though his or her purpose remains unclear.