You have to have a reinforcing effect,” says Jobling.
Establishment of such successful lineages often depends on social systems that allow powerful men to father children with multitudes of women.
The Uighurs were influenced by Christianity and, after taking control of Mongolia, went on to save the ailing Tang rulers of China from an internal revolt.
The Uighurs controlled most of Mongolia until 840 AD, when they were defeated by the Kyrgyz, who now live in the Chinese province of Xinjiang. The Largest Empire the World Has Ever Known: They remained little more than a loose confederation of rival clans until the late 12th century, when a 20 year old Mongol named Temujin emerged and managed to unite most of the Mongol tribes.
The name 'Mongol' was first recorded by the Chinese during the Tang dynasty (618-907 AD).