The Mongol Empire was the largest contiguous land empire in human history. It encompassed 9 million square miles at its peak, with some estimates placing its population as high as 100 million people — about 25% of the world at the time. And while Genghis Khan tends to receive most of the credit for that, he didn’t do it alone. There was also Subutai, a Mongol general who conquered 32 nations. Indeed, many sources claim Subutai conquered more land than anyone else in history, including suc...