In the introduction of the book, Genghis Khan created the best of the twelve worlds. They think that Genghis Khan "created the biggest empire in the world", "launched the biggest war in human history", was "the richest man in the world for thousands of years" and "the biggest winner in human history". Japanese scholar Saburo Ota called Genghis Khan "the hero of the ancient and modern world" in his book Genghis Khan. He said: "The Mongolian nation has been magnificent for 600 years. At that time, it was admired because of its vast territory.