Nezak in the context of "Alchon Huns"

The Kidarites, or Kidara Huns, were a dynasty that ruled Bactria and adjoining parts of Central Asia and India in the 4th and 5th centuries. The Kidarites belonged to a complex group of peoples known collectively in India as the Huna, and in Europe as the Chionites (from the Iranian names Xwn/Xyon), and may even be considered as identical to the Chionites. The 5th century Byzantine historian Priscus called them Kidarite Huns, or "Huns who are Kidarites". Chinese annals referred to them as the Ta Yüeh-chih, or Lesser Yüeh-chih. The Huna/Xionite tribes are often linked, albeit controversially, to the Huns who invaded Eastern Europe around the same period. They are entirely different from the Hephthalites, who replaced them about a century later.

The Kidarites were named after Kidara (Chinese: 寄多羅 Jiduoluo, MC: Kjie-ta-la) one of their main rulers. The Kidarites appear to have been a part of a Huna horde known in Latin sources as the "Kermichiones" (from the Iranian Karmir Xyon) or "Red Huna". The Kidarites established the first of four major Xionite/Huna states in Central Asia, followed by the Alchon, the Hephthalites and the Nezak.

Peroz I (Middle Persian: 𐭯𐭩𐭫𐭥𐭰, romanized: Pērōz) was the Sasanian King of Kings (shahanshah) of Iran from 459 to 484. A son of Yazdegerd II (r. 438–457), he rejected the rule of his elder brother and incumbent king Hormizd III (r. 457–459), eventually seizing the throne after a two-year struggle. His reign was marked by war and famine. Early in his reign, he successfully quelled a rebellion in Caucasian Albania in the west, and put an end to the Kidarites in the east, briefly expanding Sasanian rule into Tokharistan, where he issued gold coins with his likeness in Balkh. At the same time Iran was suffering from a seven-year famine. He soon clashed with the former subjects of the Kidarites: the Hephthalites, who possibly would have helped him gain the throne initially. He was defeated and captured twice by the Hephthalites and as a result lost his recently acquired gains.

In 482, revolts broke out in the western provinces of Armenia and Iberia, led by Vahan Mamikonian and Vakhtang I respectively. Before Peroz could quell the unrest there, he was defeated and killed in his third war with the Hephthalites in 484, who seized the main Sasanian cities of the eastern region of Khorasan−Nishapur, Herat and Marw. Taking advantage of the weakened Sasanian position in the east, the Nezak Huns subsequently seized the region of Zabulistan. Peroz was the last shahanshah to mint unique gold coins in the Indian region of Sindh, which indicates that the region was lost around the same period. Albeit a devout Zoroastrian, Peroz supported the newly established Christian sect of Nestorianism, and just before his death, it was declared the official doctrine of the Iranian church.