The emergence of the Mongol Empire in the 13th century was the turning point of human history. The dramatic change in the human world after this turning point was a positive one, especially for the Europeans. This is my belief. Before the Mongol Empire, there was no communication between the east and the west. At that time, the world was wide. Many different forms of natural barriers-rivers, mountains, deserts, impenetrable dense forests and enormously wide plains-were between them, and they didn't have any reason to cross over all of them. Communication and the exchange of ideas could now be possible after the emergence of the Mongol Empire. Gun powder, paper and compasses were introduced from the east to the west, and the concept of chemistry, astronomy and mathematics was transferred from the west to the east. Before the Mongol Empire, it was very dangerous or almost impossible to travel from the city of Venice in Italy to Beijing, China, which was a trip that Marco Polo's father Piccolo and his uncle Maffeo frequently made. After more than 20 years of staying in China, Marco Polo, who travelled to Beijing with his father and stayed there under the protection of Kublai Khan, finally returned to his home in Italy and began his storytelling, which influenced all of Europe. Marco Polo's well-known book, The Travels of Marco Polo, inspired many young men in Europe at that time to go to the east to find the riches and gold that Marco Polo described. Marco Polo's story influenced Europe inwardly and outwardly. Inwardly, it ignited the new Renaissance wave; outwardly, it motivated many men who were seeking adventure and fortune. At age 14, Christopher Columbus was one of the young men who was inspired by Marco Polo's story. His introduction of the existence of a new continent to the Europeans was a great event as everyone knows. All these were chain reactions related to Marco Polo and the Mongol Empire. Batu Khan was the front-runner by breaking the wall between the east and the west, yet his story has not been told often to the public, which motivated me to write about it. All these stories were written based on the most trusted histories. When different theories related to the same event conflicted, I picked the most probable one based on my common sense. The only fictionalized areas in this book were episodes written for the purpose of connecting stories and making the reading smoother.