Who was Genghis Khan? 

The greatest conqueror the world has ever known. The terror and scourge of civilization—half of the known world trembled under the galloping hoofs of his swift riding hordes. 

From a hunted outlaw on the bleak Mongolian plains he rose meteor-like to rule an empire vaster than any before or since. He destroyed China to provide grazing land for his horses. He defeated the flower of European Chivalry. In one battle his men killed 100,000 Turks. He razed walled towns, leaving smoking ruins. 

He made his own "ten commandments" and established a peace by terror so that it was said, "A virgin with a sack of gold could ride unharmed from one border of the nomad empire to the other."

The couriers of the Khan galloped over fifty degrees of latitude. He moved an army of a quarter of a million men two thousand miles over country a modern army could not possibly negotiate.

To him the greatest happiness was—"to crush your enemies, to see them fall at your feet--to take their horses and goods and hear the lamentations of their women."

And after he had altered the whole course of civilization he wondered why he had done it.

From the dust jacket

Harold Lamb later wrote the Landmark book Genghis Khan and the Mongol Horde.