Any book tagged with this topic discusses the Mongol Empire or is set in a time or place where the Mongol Empire plays a large role. The Mongol Empire originated in Mongolia in the 13th century under the leadership of Genghis Khan, and soon expanded to include most of Asia, Eastern Europe, and the Middle East. It was the largest land empire with adjoining borders in history. The empire collapsed in the 14th century but it left a lasting legacy, including Genghis Khan's extensive paternity. It is estimated through DNA studies that he currently has roughly 16 million living descendants.