 The name "Zübü" might be derived from Xiongnu's ruling tribe Xubu.The Zubu began paying tribute to the Khitan Empire after a campaign in 924 when the Khitan subdued the Zubu and in the region of what is now Eastern and Central Mongolia and southeastern Russia.Liao emperor Shengzong led an expeditionary force against the Zubu in 983 after the Zubu killed their own khan and began to act in defiance of the Khitan.