In the first a long time of 13th century, Genghis Khan unified the Mongolian tribes, founding the Mongolian Empire, and led them to overcome most China, Central Asia, Russia and center East. Their armies occupied a good element of European countries, too, pregnancy to at least one for the biggest empires ever. Their cavalry products, particularly their horse archers, were Genghis Khan's elite troops and handled, with tough but well coordinated costs, hitting terror for their enemies' hearts.