Xianbei state
The Xianbei state or Xianbei confederation was a nomadic empire which existed in modern-day Mongolia , Inner Mongolia , northern Xinjiang , Northeast China , Gansu , Buryatia , Zabaykalsky Krai , Irkutsk Oblast , Tuva , Altai Republic and eastern Kazakhstan from 156 to 234 . 
<triplet> Xianbei state <subj> nomadic empire <obj> instance of