And not to get like all great man history on you or anything, but the reason the Mongols came to dominate the world really started with one guy, Genghis Khan. Let's go to the Thought Bubble. The story goes that Genghis, or Chinggis Khan, was born around 1162 with the name Temüjin to a lowly clan. His father was poisoned to death, leaving Temüjin under the control of his older brothers, one of whom he soon killed during an argument. By 19, he was married to his first and most important wife, Borte, who was later kidnapped. This was pretty common among the Mongols. Temüjin's mom had also been kidnapped.