<P> In the thirteenth century , Genghis Khan expanded the Mongol Empire to be the largest contiguous empire in the world . However , within two generations , the empire was separated into four discrete khanates under Genghis Khan 's grandsons . One of them , Kublai Khan , conquered China and established the Yuan Dynasty with the imperial capital at Beijing . One family ruled the whole Eurasian land mass from the Pacific to the Adriatic and Baltic Seas . The emergence of the Pax Mongolica had significantly eased trade and commerce across Asia . </P>
by the 13th century the blank was the largest land empire at that point
Mongol Empire