Xionites, Chionites, or Chionitae (Middle Persian: Xiyon; Avestan: Xiiaona; Sogdian: Xwn; Pahlavi: Huna), or Hunni, Yun or Xūn (獯), were an Iranian-speaking people who were prominent in Transoxania and Bactria. The Xionites (Chionitae) are first mentioned with Kushans (Cuseni) by Ammianus Marcellinus who spent the winter of 356-57 CE in their Balkh territory. They arrived with the wave of immigration from Central Asia into Iran in late antiquity.