Genghis Khan Didn't Bring Down Central Asia's Medieval River Civilizations. But Climate Change Did

In 1206, Genghis Khan began the Mongol invasion, leading a horse-driven bow-wielding military force that swept through much of modern-day Asia into the Middle East and Eastern Europe. Over the course of the century-and-a-half run of the Mongol Empire, about a quarter of the world's total land area was conquered and an estimated 40 million people were slaughtered. Today, the name of Genghis Khan remains a byword for brutality, terror and military power. But, according to new research, Khan had an unexpected ally in his conquests: climate change.