When there is a concerted move to change an established power base, it seems inevitable that mass murder will result. Genghis Khan came from a poor family but became a leader of genius who managed to unite widespread pockets of Mongols into one force under his family rule.
This nomadic group ultimately became the Mongol Empire. This was so huge that it stretched from the Adriatic coast to the Pacific coast. In order to achieve this, millions of remote peoples were plundered and conquered.
Mongols are the people who live in Mongolia. Mongolia is a country that is directly north of China. In history, the Chinese were attacked by the Mongols coming into their country. This caused the Chinese to build the Great Wall of China. Even though the Great Wall was constructed during different dynasties, it was used to protect the attackers of the Mongols on the Chinese people. Just like all other countries and groups of people in ancient times, they were trying to get more land for their country.
Plus, Mongols and others wanted to acquire more products that were being grown from other civilizations. The Mongols have been known as attackers because they did travel to many different countries to invade and try to claim land from these countries by force.