Foremost, the Mongols produced a charismatic leader, Genghis Khan, who united the Mongol tribes in a dream of conquest and expansion.The Mongolian horse, a small and very tough infantry horse which could move very quickly and run long distances. Mongol troops were all horse-mounted and could move very quickly.The Mongol bow was a very small composite bow which could accurately shoot an arrow more than 200 yards. Combined with the fast-moving horse mounted infantry, the Mongols had a great advantage.Mongol tactics focused on speed and mobility. If a city quickly surrendered, they were lenient, but if it resisted, they were ruthless.When necessary, the Mongols were willing to co-opt needed talent. For instance, when they needed to lay siege to a city, they would rely on Chinese siege engineers to lay siege to Baghdad. Compared to the empires they conquered, they weren't racist in how they used people.