The bishop of Acre was correct in thinking that a great king had conquered Persia; however "King David", as it turned out, was the Tengrist Mongol ruler, Genghis Khan. His reign took the story of Prester John in a new direction. Though Genghis Khan was at first seen as a scourge of Christianity's "enemies", he proved to be tolerant of religious faiths among those subjects that did not resist the empire and was the first East Asian ruler to invite clerics from three major religions (Christianity, Islam, and Buddhism) to a symposium so that he might learn more about their beliefs. The Mongol ruler was also reputed to have a Nestorian Christian favorite among his many wives, whom the Europeans imagined as influential in the disastrous Mongol sack of Baghdad.