Briefly before Mongols, JIN(金) dynasty. Jurchen tribes almost conquered Song.

and during The Tsin Dynasty, Five Hu disordered China, Han Chinese were almost eaten and killed to extinct, XiongNu and Jie army slaughtered everyone when they conquered a place. latter, one Chinese king 冉闵 gave the order to kill all the five barbarians, almost extincted Jie, literally killed the barbarians out of China. truly, one of the bloodiest period of time in the whole history of China.