Insults draws Genghis westward. “I am master of the lands of the rising sun while you rule those of the setting sun. Let us conclude a firm treaty of friendship and peace.” With those words, perhaps embellished by zealous scribes, Genghis Khan seeks amity with Shah Muhammad of the Khwarizm Empire, an expanse to the south and east of the Caspian Sea. Powerful and arrogant, Muhammad keenly distrusts Genghis. He accepts the olive branch but later kills a Mongol envoy, sending the unfortunate man’s head back to Genghis. Seething, the Mongol leader roars at the heavens: “I was not the instigator of these tribulations. Grant me the strength to exact vengeance!”   © 1997 National Geographic Society. All rights reserved.