Sasanian History: From Ardashir to Yazdegerd

The Sasanian Empire is the best documented of the three classical Persian empires, and the most difficult to summarise. The Achaemenid Empire is documented mainly by Greek observers who were often hostile; the Parthian Empire is documented mainly by Greek and Roman sources that are intermittent and interested; the Sasanian Empire is documented by a thicket of Greek, Latin, Syriac, Armenian, Arabic, Chinese, and Middle Persian texts, together with a substantial body of rock reliefs, seals, coins, and archaeological remains. The result is a more complete picture, but a more complicated one. The Sasanian period does not have a single organising story in the way the Achaemenid period does (Cyrus, Darius, Xerxes, fall) or the Parthian period does (Arsaces, Mithridates, Carrhae, Sasanian revolution). It has at least three: the Zoroastrian revival, the long war with Byzantium, and the Arab conquest. Trying to tell all three at once is the recurring problem of every general history of late antique Iran.

This article is a chronological overview, with attention to the moments when the three stories converge.

The founding (c. 205–241 CE)

The Sasanian dynasty took its name from Sasan, a priest or local notable of the temple of the goddess Anahita at Istakhr in Persis. Sasan’s son Papak seized the throne of the local kingdom of Persis from its Arsacid governor around 205 CE and was the first of the family to call himself king. Papak’s son Ardashir — the future Ardashir I — expanded his power rapidly. By about 220 CE Ardashir had absorbed the kingdom of Elymais and the Mesopotamian cities along the Diyala, and was intervening in the affairs of the declining Arsacid empire. The decisive moment came in 224 CE, at the Battle of Hormizdagan, where Ardashir defeated and killed the last Arsacid king of kings, Artabanus IV, and proclaimed himself successor to the Achaemenids. The new dynasty would rule Iran for more than four centuries.

The Sasanian revolution was a fundamental change in the character of the Iranian state. The Arsacid monarchy, with its diffuse system of noble-led government and its hybrid Greek-Iranian culture, was replaced by a centralised, militarily aggressive, self-consciously Zoroastrian state. The Sasanian kings stripped the great noble families of much of their political independence, established a centralised bureaucratic monarchy, and reorganised the Zoroastrian church as an arm of the state. The transformation was not complete — the great families would reassert themselves in the third and fourth centuries, and the Sasanian monarchy would always be more of a coalition than an absolute state — but the change of direction was real. Touraj Daryaee’s Sasanian Persia: The Rise and Fall of an Empire (2009) is the most useful single-volume treatment; Parvaneh Pourshariati’s Decline and Fall of the Sasanian Empire (2008) is the indispensable revisionist account of the dynasty’s later politics, and is, in my view, the more important of the two for understanding the structure of the state. Klaus Schippmann’s Grundzüge der Geschichte des sasanidischen Reiches (1980) is the older German synthesis, still useful for the chronology.

The first great period: Shapur I (240/241–272 CE)

The reign of Shapur I was the first great period of Sasanian imperial power. Shapur fought three Roman emperors and won, more or less decisively, against all of them. He defeated Gordian III in 244, agreed to a peace with Philip the Arab later that year, fought a long inconclusive war with the emperor Valerian, and in 260 CE captured Valerian at the Battle of Edessa — the first time a Roman emperor had been taken alive by a foreign enemy. Lactantius’ De Mortibus Persecutorum and the Sasanian rock reliefs at Naqsh-e Rajab and Bishapur preserve the Sasanian version; the Roman sources give the Roman humiliation. Shapur used his victories to push the Sasanian frontier deep into Roman territory, taking the Roman provinces of Syria, Cilicia, and Cappadocia, and sacking Antioch.

The headline of the reign is the capture of Valerian. The longer-term effect was the foundation of the Sasanian administrative, military, and religious system. The Res Gestae Divi Saporis, the great trilingual inscription at Naqsh-e Rajab, is the most important Sasanian royal inscription to survive, and the principal primary source for the early Sasanian period. Matthew Canepa’s The Two Eyes of the Earth (2009) reads the rock reliefs of Shapur as a coherent statement of Sasanian royal ideology; the reading has been broadly accepted and is, to my mind, the most useful piece of art-historical work on the Sasanian period.

The third and fourth centuries

The Sasanian kings of the third and fourth centuries faced a series of challenges from Rome, the Central Asian nomads, and the Zoroastrian church. Bahram II (r. 276–293 CE) consolidated the Sasanian hold on the eastern provinces and persecuted the Manichaeans, a new religious movement founded by the prophet Mani (d. c. 274 CE) that briefly threatened the Zoroastrian establishment. Narseh (r. 293–302 CE) fought a major war with the Roman emperor Diocletian, which ended in a negotiated peace. Shapur II (r. 309–379 CE), the longest-reigning of all Sasanian kings — sixty-eight years on the throne, a record for pre-modern Iran — fought major wars with the Roman emperor Constantine and his successors, consolidated the Sasanian hold on Armenia, and presided over a long period of internal prosperity. The reign of Shapur II is treated in detail by Timothy Barnes, Constantine and Eusebius (1981), and by Noel Lenski’s Failure of Empire (2002); both are useful for the Roman side of the picture.

The Zoroastrian church, by Shapur II’s reign, had been reorganised as a state institution with judicial authority, a hierarchy of mobads (priests), and a network of fire temples and religious schools. The Dastur-namag and the Bundahishn, the great Pahlavi texts of the Sasanian period, were probably compiled in their earliest forms in this period. The dating is contested; Mary Boyce’s classic treatment in A History of Zoroastrianism (vol. II, 1982) is still the working reference, although her chronology has been revised by later scholars (notably Shaul Shaked and Prods Oktor Skjærvø).

The fifth century

The fifth century brought a series of crises. Yazdegerd I (r. 399–420 CE), nicknamed “the Sinner” by the Zoroastrian priesthood for his tolerance of Christians, was in fact a successful and well-liked king; the “Sinner” (Wuzurgmidad) epithet properly belongs to his chief minister, a Christian sympathiser whose name the clergy applied to the reign by association. Bahram V (r. 420–438 CE), the famous Bahram Gur of the Persian national epic, was celebrated for his hunting prowess and his romance with the Indian princess Sepid; he was a competent king who dealt firmly with the revolt of the Armenian nobility in 451 (the Battle of Avarayr, in which the Armenian general Vardan Mamikonian fell, is a fixed point of Armenian national memory). The Hephthalite invasions of the 480s and 490s killed the Sasanian king Peroz I in 484 CE and forced the Sasanians to pay tribute for several decades. The Hephthalites — the “White Huns” of older literature — were a serious threat to the Sasanian eastern provinces, and the Sasanian kings of the late fifth and early sixth centuries had to balance their resources between the Hephthalite threat in the east and the Roman threat in the west.

The sixth century: Khosrow I Anushirvan (531–579 CE)

The reign of Khosrow I Anushirvan is generally considered the high point of the Sasanian state. Khosrow came to the throne after a long period of instability that included the reign of his father Kavad I, the so-called Mazdakite movement (a radical religious and social movement, suppressed violently by Khosrow in 528/529 CE), and the Hephthalite pressure. Khosrow fought a long war with the Byzantine emperor Justinian (540–562 CE), capturing Antioch in 541 and forcing the Byzantines to a peace that involved substantial annual payments to the Sasanian treasury. Khosrow destroyed the Hephthalite empire in 557 CE in a coalition with the Göktürks, and he fought a second war with the Byzantine emperor Tiberius in 576–579 CE.

Khosrow was also a great reformer. He reorganised the Sasanian tax system on the basis of a cadastral survey of the empire’s agricultural land, reformed the legal system, and patronised the Academy of Gondeshapur, the major centre of learning in the Sasanian world. The Sasanian rock reliefs at Taq-e Bostan, the famous Carpet of the Spring of Khosrow (probably legendary, but a fixed point of the Sasanian cultural tradition), and the great Sasanian silver plate of the sixth century are all products of his reign or its immediate aftermath. James Howard-Johnston’s The Last Great War of Antiquity (2021) is the most thorough treatment of the Sasanian–Byzantine war of 602–628, and reads the Sasanian century of Khosrow I and his grandson Khosrow II as the high point of a long strategic contest.

The seventh century: collapse

The reign of Khosrow II (r. 590–628 CE) was the last great period of Sasanian power. Khosrow II came to the throne with the support of the Byzantine emperor Maurice, who had helped him overthrow his predecessor. The murder of Maurice by the usurper Phocas in 602 gave Khosrow a pretext for a major invasion of the Byzantine East. The Sasanian armies conquered the Byzantine Near East, Egypt, and parts of Anatolia, and at the height of the war in 615–621 Khosrow’s forces reached the Bosphorus and captured Jerusalem, taking the Holy Cross as a trophy. The war was reversed by the Byzantine emperor Heraclius, who launched a series of brilliant campaigns in 622–628 CE that ended with the recovery of the lost territories and the restoration of the Byzantine frontier.

The wars had, however, fatally weakened the Sasanian state. Khosrow II was overthrown and killed in 628 CE, and a series of civil wars followed in which at least eight, possibly more, different claimants to the throne competed for power. The last Sasanian king of kings, Yazdegerd III — a youth, probably 8 to 21 at his accession — came to the throne in 632 CE and ruled an empire in chaos. He was defeated at the Battle of al-Qadisiyyah in 636 CE, lost Ctesiphon in 637 CE, and was killed near Merv in 651 CE. The Sasanian dynasty, after more than four centuries of rule, was at an end.

The pattern is hard to miss. The Sasanian state was, throughout its history, the most powerful political entity of the Iranian plateau, but it was a coalition rather than an absolute state, and the coalition fractured whenever the royal centre was weak. The Sasanian century of Khosrow I and Khosrow II was the period in which the coalition held together, and the period after 628 CE was the period in which it did not. The Arab conquest was the final blow, but it was a blow delivered to a state that was already in pieces.

The legacy

The Sasanian state, although destroyed, left a substantial legacy. The Sasanian system of provincial administration, the Sasanian tax system, and the Sasanian tradition of royal patronage of the arts were all adopted by the early Islamic caliphate and by the later Iranian, Turco-Iranian, and Mongol dynasties. The Sasanian art of rock relief, silver plate, and silk textiles was imitated in the Islamic, Byzantine, and medieval European worlds. The Sasanian tradition of kingship, in which the shahanshah stood at the intersection of heaven and earth and ruled by divine favour, was so compelling that it was adopted, with modifications, by the caliphs of Islam themselves. The Sasanian model of the Zoroastrian state church, the Sasanian tradition of monumental architecture, and the Sasanian vocabulary of power all survived the Arab conquest and shaped the political, cultural, and religious traditions of the Islamic world. The Sasanian period is, in the historical sense, the bridge between the ancient and the medieval Near East.