When Marco Polo arrived, China’s ruler, Kublai Khan, was the grandson of the Mongol leader Jenghiz Khan. History generally treats the Mongols unkindly, emphasizing their ferocious military campaigns. The Mongols were nomads from central Asia, survivors of a harsh climate. For centuries they were only one among a number of nomadic tribes on the Asian steppes, often engaged in wars with their neighbours and among themselves. That all changed with Jenghiz Khan.
In 1187, leaders of various Mongol clans approached Temujin and promised him their allegiance. They elected him Khan and gave him the name Jenghiz. With his people united behind him, Jenghiz undertook the greatest campaign of conquest that history had ever seen. Using speed and surprise and deadly archery, the Mongols moved into China, Afghanistan, Persia, Armenia, Russia and eastern Europe. Central to the success of the Mongol victories were the steppe ponies that the warriors rode. Short and stocky with a dense coat, these ponies could carry the horsemen great distances.
Jenghiz died in 1227, master of the greatest empire ever created in one man's lifetime. The Mongol nobles elected his third son, Ogedei, to succeed his father. Ogedei continued his father's expansion into northern China in 1234 and his armies were at the gates of Vienna when he died in 1241. Kublai Khan was the first foreigner ever to rule China and he adopted many Chinese customs while maintaining his Mongol heritage.
After Kublai's death the empire gradually disintegrated. The Mongols were gradually pushed back into their original domains in mid-Asia.
Learn more: The Mongols in China