As the western Roman empire declined during the fourth and fifth centuries AD, Europe lost contact with the rest of the world. Classical knowledge of the outside world receded, and what emerged in its place was a peculiar mixture of fact and fiction. European scholars inhabited the lands to their east with unicorns, cyclops, and other fantastic creatures. One persistent rumor spoke of the barbarian tribes of Gog and Magog whom Alexander the Great had supposedly imprisoned behind giant brass gates somewhere in the East. It was said that the escape of Gog and Magog would signal the imminent end of the world.
With the gradual revival of commerce during the thirteenth and fourteenth centuries, Europeans once more began to venture beyond their borders and returned to tell of what they had seen. But these travellers, upon their return from faraway lands, seldom gave what we would consider to be factual accounts. Instead, they related bizarre stories that confirmed the existence of the imaginary kingdoms and creatures that Europeans had so long dreamed about and feared.