And we think that Game of Thrones is complex.  In one century, from 1206, when Genghis Khan was born, through 1294, when Khubilai Khan died, the Mongols spread from a small group of nomads on the steppes of what is now Mongolia to control all of Russia, northern India, Persia, Iraq and China.  

Inventive warfare, featuring swift warriors shooting arrows from galloping horses, overwhelmed rigid peasant armies and fully armed, mounted knights.  Mongols attacked front on, while stealth battalions came from the rear, crushing the enemy between the two.  The Mongols did not always exterminate the conquered.  They demanded loyalty and taxes.  If there was no pledge of loyalty, you were exterminated.  Where inhumane systems governed, they supplanted it with religious tolerance, rights for women, and learning.  Originally the Mongols were illiterate nomads.  When exposed to systems of writing, accounting, teaching, they brought these skills to their people and to other, less developed, cultures.  While Europe was in the Dark Ages, the Mongol Empire and culture flourished

As nomads, their focus was always on trade routes.  Mongols opened all the groups they conquered to international trading, developing the Silk Road and the system of caravanserais, motels of the ancient world build one camel-day journey apart.  At the caravanserais, all were welcome, baths were available, food was available, merchants could store goods to reclaim as they returned.  What they paid was tax in return for the services.  

Genghis Khan and the Making of the Modern World is not an easy read because there are so many important characters spread over such vast territory.  Jack Weatherford is an academic who spent years on the ground researching this book.  He presents the material in a logical and thorough manner.   This is a worthy read for armchair travelers and historians—eye opening to say the least.