Genghis: Lords of the Bow, Paperback

For centuries, primitive tribes have warred with one another. Now, under Genghis Khan a man who lives for battle and blood they have united as one nation, overcoming moats, barriers, deceptions, and superior firepower only to face the ultimate test of all: the great, slumbering walled empire of the Chin.
Genghis Khan comes from over the horizon, a single Mongol warrior surrounded by his brothers, sons, and fellow tribesmen. With each battle his legend grows and the ranks of his horsemen swell, as does his ambition. In the city of Yenking modern-day Beijing the Chin will make their final stand, confident behind their towering walls, setting a trap for the Mongol raiders. But Genghis will strike with breathtaking audacity, never ceasing until the emperor himself is forced to kneel."