ABSTRACT
When the Mongols vanished as suddenly and unexpectedly as they had come, departing from Hungary at the very moment when Europe was beginning to recognise how deadly was the peril which threatened its whole existence. Many investigators believe that a considerable part of the pessimism which affects Europe even to-day is the outcome of the subconscious and obscure anxiety roused in us by the notion of the "Yellow Peril"—a vestigial survival of the Mongolian terror of seven hundred years ago. `The upshot was that Pope Innocent IV, decided to send a letter "to the King and the people of the Tartars" in which he exhorted them to abstain from attacking and persecuting the Christians, threatening them with the wrath of God in this world and damnation in the life to come. In the European camp there were many Nestorian Christians, and numerous prisoners from Hungary and Russia with whom they conversed.
