Warring patrilineal clans may have wiped out large swathes of the male population 5,000 to 7,000 years ago.
From Genghis Khan to Alexander the Great, get the facts on seven historical titans whose final resting places are unaccounted for.
More than 10,000 volunteers spent 30,000 hours scanning satellite images of Mongolia in search of the long-hidden tomb of warlord Genghis Khan.
Archaeologists working along the Volga River in Russia have uncovered the remains of a 750-year-old city ruled by the descendants of Mongol warrior Genghis Khan.
Explore 10 facts about a great ruler who was equal parts military genius, political statesman and bloodthirsty terror.