The Rain Allowed the Mongols to Leave the Plain
Warm, wet years on the Steppes of Central Asia provided the resources for the Mongol armies to conquer Asia.
Genghis Khan and his Mongol soldiers swept out of the grassland Steppes of central Asia in the 13th century, and conquered a good portion of the world. Historians have long debated what allowed a group of nomadic animal-herders to become such a powerful military force. Now Dr. Amy Hessl, a professor of Geography at West Virginia University, and her colleagues think it might be as simple as rain. Dr. Hessl's group analyzed tree rings to reconstruct the historical climate of Mongolia and found that the rise of the Mongol empire was a particularly warm, wet period on the normally arid steppes, which meant more grass for the Mongol's livestock, and a surplus of food and labour that fuelled the rise of the empire.