**A landmark biography by the New York Times bestselling author of Genghis Khan and the Making of the Modern World that reveals how Genghis harnessed the power of religion to rule the largest empire the world has ever known. ** Throughout history the world's greatest conquerors have made their mark not just on the battlefield, but in the societies they have transformed. Genghis Khan conquered by arms and bravery, but he ruled by commerce and religion. He created the world's greatest trading network and drastically lowered taxes for merchants, but he knew that if his empire was going to last, he would need something stronger and more binding than trade. He needed religion. And so, unlike the Christian, Taoist and Muslim conquerors who came before him, he gave his subjects freedom of religion. Genghis lived in the 13th century, but he struggled