Peroz I () was the Sasanian King of Kings () of Iran from 459 to 484. A son of Yazdegerd II (), he rejected the rule of his elder brother and incumbent king Hormizd III (), 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 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.
Peroz's wars against the Hephthalites have been described as "foolhardy" in both contemporary and modern historiography. His defeat and death initiated a period of political, social and religious tumult. The empire reached its lowest ebb; the was now a client of the Hephthalites and was compelled to pay tribute, while the nobility and clergy exerted great influence and authority over the nation, being able to act as king-makers. The magnates—most notably Sukhra and Shapur Mihran—elected Peroz's brother, Balash, as the new . Order would first be restored under Peroz's son Kavad I (), who reformed the empire and defeated the Hephthalites, reconquering Khorasan. By 560, Peroz had been avenged by his grandson Khosrow I (), who with the help of the First Turkic Khaganate, destroyed the Hephthalites.
Name "Peroz" is a Middle Persian name, meaning "victorious". It is attested in Parthian as , whilst its New Persian form is (Arabicized form: ). Peroz is transliterated in Greek as (). The Georgian transliteration of the name, , was introduced into Georgian twice; through its Middle Iranian form (Parthian/Middle Persian) and in the New Persian form. The Armenian transliteration, (), follows the exact same spelling as the Middle Persian original. The name Peroz had already been in use by members of the Sasanian family in the 3rd century, namely by the Kushano-Sasanian ruler Peroz I Kushanshah.
Rise to power
When Peroz's father Yazdegerd II () died in 457, he had reportedly not designed a successor and instead—according to the medieval historian al-Tha'alibi—entrusted the task to the elite and the leading (margraves). Civil war soon followed; Yazdegerd II's eldest son Hormizd III declared himself king at the city of Ray in northern Iran, while Peroz fled to the northeastern part of the empire and began raising an army in order to claim the throne for himself. The brothers' mother, queen Denag, temporarily ruled as regent of the empire from its capital, Ctesiphon. According to eastern sources, Peroz was more worthy for the throne than Hormizd, who they refer to as "unfair". Only the anonymous source known as the Codex Sprenger 30 describes Hormizd as the "braver and better", while describing Peroz as "more learned in religion".
Both brothers seemingly attempted to gain the support of the powers of the neighbouring eastern region of Tokharistan/Bactria in their struggle. The region was then controlled by the Kidarites, along with some of their local vassals, such as the Hephthalites. According to three contemporary letters in the Bactrian language (the language of Tokharistan), the local ruler of the city of Rob (between Kabul and Balkh) Kirdir-Warahran, is given the honorific titles of "glorious through Hormizd" and "true to Peroz", which seemingly indicates that he shifted his allegiance between the two brothers. According to the contemporary Armenian historians Elishe and Ghazar Parpetsi, Peroz was notably supported by the House of Mihran, one of the Seven Great Houses of Iran, while later Persian sources instead report that Peroz fled to the Hephthalites and enlisted their help.
This version, however, has been called "legendary" and "somewhat fanciful" by modern historians. The modern historians Parvaneh Pourshariati, Shapur Shahbazi and Michael Bonner prefer the Armenian version, with the latter suggesting that the Persian account may yield some authenticity, with Peroz enlisting Hephthalite aid through the Mihranids. Elishe and Ghazar give two slightly different accounts of Peroz's struggle against Hormizd. According to the former, Peroz was aided by his Mihranid tutor Raham Mihran, who in 459 captured and executed Hormizd, and then crowned Peroz as . The same account is given by Ghazar, with the exception that the Mihranid is named Ashtad Mihran, and was not the tutor, but rather foster father of Peroz.
Reign Revolt in Caucasian Albania and famine During the dynastic struggle between Peroz and Hormizd III, the Arsacid king of Caucasian Albania, Vache II (), took advantage of the tumultuous situation and declared independence. He allowed the Huns into the city of Derbent, and with their aid attacked the Iranian army. Peroz responded by allowing the Huns to pass through the Darial Gorge, and they subsequently ravaged Albania. The two kings negotiated an accord; Vache II would return his mother (Peroz's sister) and daughter to Peroz, while he would receive the 1,000 families he had originally been given by his father as his share of the inheritance. Vache II abdicated in 462, leaving Albania kingless until 485, when Vachagan III () was installed on the throne by Peroz's brother and successor Balash (). Peroz also freed some of the Armenian aristocrats who had been jailed by his father in the aftermath of the Armenian uprising in 451. The previous year (461), Iran suffered from a severe drought, which caused a large-scale famine that would last until 467.
Relations with the Byzantine Empire
Early in Peroz's reign, tensions began to rise between Iran and Byzantium. In the mid-460s, the Byzantines discovered that their general Ardaburius had been secretly corresponding with the Iranian court, urging Peroz to attack the Byzantines, with the promise of military support and presumably also intelligence. Ardaburius's letters were intercepted and given to Byzantine emperor Leo I (), who had him removed from office and summoned to the capital, Constantinople. Ardaburius's fate is not known. Leo responded to the Iranian activity by reinforcing his borders with them, which included the fortification of Callinicum in Syria.
Since the Byzantine–Iranian peace treaty of 387, both empires had agreed that they were obligated to cooperate in the defense of the Caucasus against nomadic attacks from the northern steppes. The Iranians took the major role in this, while the Byzantines contributed roughly of gold at irregular intervals. The Byzantines saw this payment as a contribution to their mutual defense, but the Iranians saw it as tribute which established Byzantium as a subordinate of Iran. Since the foundation of the Sasanian Empire, its rulers had demonstrated the sovereignty and power of their realm through collection of tribute, particularly from the Byzantines. Retaliating for Iran's plot with Ardaburius, Leo stopped the payments. Repeated negotiations failed to resolve the issue. The Byzantines also appealed for the return of the city of Nisibis, which had been ceded to Iran as part of a treaty in 363. Tensions continued to increase until the accession of the Byzantine emperor Zeno () in 474, who resumed payment to Iran and also ransomed Peroz from captivity by the Hephthalites. Regardless, war almost erupted in the early 480s, when some Tayy clients of the Sasanians made incursions into Byzantine territory due to suffering from a two-year drought. The Iranian general Qardag Nakoragan, who was stationed at the frontier, quickly pacificed the Tayy raiders and ensured peace with the Byzantines.
War with the Kidarites
Since the reign of Shapur II (), Iran had to deal with nomadic invaders in the east known as "Iranian Huns" and made up of Hephthalites, Kidarites, Chionites and Alkhans. They seized Tokharistan and Gandhara from Shapur II and his Kushano-Sasanian clients, and eventually Kabul from Shapur III (). Archaeological, numismatic, and sigillographic evidence demonstrates that the Huns ruled a realm just as refined as that of the Sasanians. They swiftly adopted Iranian imperial symbolism and titulature, such as imitating Sasanian imperial coinage. The modern historian Richard Payne states: "Far from the destructive xyonan of the Iranian accounts or the marauding barbarians of the Roman historians, the Hun kingdoms of post-Iranian Central Asia were city-based, tax-raising, ideologically innovative states the kings of kings found themselves hard pressed to unseat." The loss of the Armenian cavalry contingent after the revolt of Armenia in 451 weakened Sasanian efforts to keep their eastern enemies in check.
The Sasanian efforts were disrupted in the early 5th century by the Kidarites, who forced Yazdegerd I (), Bahram V (), and/or Yazdegerd II to pay them tribute. Although this did not trouble the Iranian treasury, it was nevertheless humiliating. Yazdegerd II eventually refused to pay tribute, which would later be used as a justification for the war that the Kidarites declared against Peroz in 464. Peroz lacked enough manpower to fight, and therefore asked for financial aid from the Byzantine Empire, which declined. He then offered peace to the king of the Kidarites, Kunkhas, and offered his sister in marriage, but sent a woman of low status instead.
After some time Kunkhas found about Peroz's deception, and in turn attempted to trick him, by requesting him to send military experts to strengthen his army. When a group of 300 military experts arrived at the court of Kunkhas at Balaam (possibly Balkh), they were either killed or disfigured and sent back to Iran, with the information that Kunkhas did this due to Peroz's false treaty. Around this time, Peroz allied himself with the Hephthalites and other Huns, such as Mehama, the ruler of Kadag in eastern Tokharistan. With their help, he finally vanquished the Kidarites in 466, and brought Tokharistan briefly under Sasanian control, issuing gold coins at Balkh. The style of the gold coin was largely based on the Kidarite coins, and displayed Peroz wearing his second crown. The legend of the coin displayed his name and title in Bactrian. The following year (467), an Iranian embassy journeyed to Constantinople, where the victory over the Kidarites was announced. An Iranian embassy sent to the Chinese Northern Wei dynasty in 468 may have done the same.
The Kidarites continued to rule in Gandhara, and possibly Sogdia. They were eventually conquered by the Alkhans in Gandhara, and by the Hephthalites in Sogdia. According to Bactrian chronicles, Mehama was subsequently promoted to the position of "governor of the famous and prosperous king of kings Peroz". However, a power vacuum followed in Tokharistan, which allowed Mehama to gain autonomy, or possibly even independence.
First and second war with the Hephthalites