 Tribes known as the "Weak Xiongnu" or Yueban took advantage of the vulnerability of the neighboring Uar (a people possibly linked to the Hephthalites and/or the "Avars" who later invaded Eastern Europe) and conquered Zhetysu, where they established the principality of Yueban.Later, some Uar returned to Zhetysu, and in cooperation with the Mukrins, a Xianbei tribe, occupied the Tianshan slopes in the 2nd century, retaining their independence for some time as the Western Xianbei Horde.Zhetysu was also populated by the Azi (who lived between Suyab and Uzkent) and the Tuhsi.