The
Kumo Xi (; called the
Xi since the
Sui dynasty (581-618 AD)), also
Tatabi, were a
Mongolic steppe people located in current
northeast China from 207 AD to 907 AD. After the death of their ancestor
Tadun in 207 they were no longer called
Wuhuan but joined the
Khitan Xianbei in submitting to the
Yuwen Xianbei. Their history is widely linked to the more famous
Khitan. During their history the Kumo Xi engaged in conflict with numerous Chinese dynasties and with the Khitans, eventually suffering a series of disastrous defeats to Chinese armies and coming under the domination of the Khitans. In 1007, the Kumo Xi were completely assimilated into the Khitan
Liao Dynasty.