Unlike generals who had grown up with cities and had access to centuries-old besieging techniques, Genghis Khan had to invent his own methods. He quickly learned the simple tactics, such as cutting off the Mongols’ enemies from the surrounding food supply, but he soon attempted more unorthodox methods, such as when he attacked the fortified Tangut capital by diverting a channel of the Yellow River to flood it. With their inexperience in engineering, the Mongols succeeded in diverting the river, but they wiped out their own camp instead of the Tangut.
