From Mongolia to Turkey, thanks to discoveries made in four lost cities dating back to the Middle Ages, historians and archaeologists reveal how Gengis Khan, founder of the Mongol Empire, and his descendants managed to maintain order and peace within the largest contiguous empire in history.

Far from the cliches associated with barbarian warriors, the Mongols, a nomadic peoples, proved to be shrewd politicians and more surprisingly, great builders of cities, where a peaceful and multicultural society thrived.