Genghis: Lords of the Bow (Conqueror, #2)

Genghis unites Mongol tribes to cross the Gobi Desert and fight the Chin - gleaming cities, soaring walls, and canals. Laying siege to one fortress after another, Genghis cunningly crushes each enemy differently, overcoming moats, barriers, deceptions, and superior firepower—until his army calls the Emperor in Yenking to kneel.