On the forty-second page of “Empire of Debt: The Rise of an Epic Financial Crisis” authors William Bonner, & Addison Wiggin wrote (emphasis added):
of property rights or the division of labor. Things got simpler, more brutal, mean, and nasty; lives were shortened. It was not a time to be in the insurance business.
What caused the periodic invasions no one knows. Perhaps good weather out on the plains produced population explosions that caused the nomads to expand. Perhaps bad weather caused famine that sent hungry mouths in search of someone else's meat and grain. Historians don't know. But fear of the barbarians from the steppes has been a chronic theme of Western history—particularly among the Teutonic tribes that were most exposed to them.
The Great Khan
Perhaps the most successful empire builder of all time was a leader of one of those periods of barbarian expansion—Genghis Khan. Since the time of the Romans, it has been fashionable to put a civilized mask on your face when you put the imperial purple on your back. You are bringing religion to the heathen. You are bringing civilization to the indigenes. You are bringing culture, education, and technology. Even Alexander the Great thought he was doing the world a favor. Conquerors do not like to admit—even to themselves—that their instincts are no different from those of barbarians. They have better table manners. But they are subject to the same urges as Genghis or Attila. Bloodlust, prestige; power, status—who can deny that it would be a thrill to conquer a whole city or an entire nation? But empire builders typically put on the imperial purple like a set of angel's wings, leap off the balcony, and come down with a thud.
Genghis Khan needed no mask. The man showed his face as it really was. He united the Mongolian tribes in about 1129 and beginning with a series of attacks on northern China, he embarked on a spectacular epic of mass slaughter and rapine from which two empires were derived. One of them, the Ottoman Empire, lasted until the end of World War I. The Mongol hordes overran northern China, Tibet, Persia, nearlly all of central Asia and the Caucasus, Korea, Burma, Vietnam, Anatolia, and much of Russia. They attacked India and eventually, in 1526, Babar, one of Genghis Khan's descendants, set himself up as emperor of the place. In China, too, Genghis's descendants founded the Yuan dynasty, which ruled until nearly the fifteenth century.