Lessons from the Last Empire of Iran
Cameo depicting equestrian combat between Sasanian king Shapur I and Roman emperor Valerian, at the Battle of Edessa in 260.

Lessons from the Last Empire of Iran

Michael Bonner
Michael Bonner
10 min read

By the mid-620s, the Persian king Khusro II had conquered most of the Eastern Roman Empire. A final push toward Constantinople was planned. The armies of Iran and her nomadic allies of the steppe were to descend upon the capital, blockade it by land and sea, and receive the emperor’s surrender. The nobles and retired worthies of the Roman Senate had earlier sent a grovelling letter to the Persian government, urging Khusro to impose a client king over them and spare what was left of the empire. But Khusro ignored it.

For a moment, the extinction of 800 years of Roman rule in the Mediterranean world hung in the balance. Khusro’s authority now stretched from the Nile to the Euphrates and from the Tigris to the Indus, and was about to be extended into Europe. Like his Persian forebears Cyrus and Darius, he commissioned monumental rock reliefs to commemorate his conquests. His vast empire might have lasted for centuries, binding together the fringes of Europe with North Africa and the Levant with the Iranian plateau, and connecting them all with the world of the Asiatic steppe, and perhaps even with India and China. For the first time in history, the most civilised peoples of western Eurasia might constitute a single polity.

Our world would now be fundamentally different. Instead of shifting ever further westward, the centre of the Christian world would have remained in the East under the patronage of the Persian king. Instead of dwindling and almost disappearing, the Zoroastrian religion would have remained the faith of a triumphant elite. Under the watchful eyes of Persian viceroys and client kings, Arabia would have remained quiescent; and the preaching of Muhammad confined to a local following. The sub-Roman world in western Europe might never have developed any political unity, and might have been as wild as the northern borderlands of China in the pre-modern era. And there would have been no impetus to cross the Atlantic and settle in the New World.

But this is not how real history unfolded. The Roman emperor Heraclius led an astounding counterattack through Armenia, and took the fight toward the Persian capital of Ctesiphon, in Mesopotamia. A Roman alliance with the Turkish nomads of Inner Asia brought the foremost military power of the age into the war, and the Turks destroyed the Iranian border defences in the Caucasus. These defeats put the reign of Khusro II under enormous strain. On the night of February 28th, 628, Khusro’s own son led a cabal of nobles to overthrow him and make peace with Rome.

But not even this settlement lasted. The tribes of the Arabian Peninsula, inspired by a new religion, embarked upon a project of world conquest. In less than a generation, the entire Iranian empire had fallen, and only the Roman rump state, which we call Byzantium, remained of the old binary world order. The future belonged to the Arab caliphs ruling amidst the ruins of the Greco-Roman and Iranian civilisations.

Sadly, this story will not be well-known to most of my readers. It is impossible for many people even to imagine Iran as the other great power of the ancient world. Historians dwell too much on Greco-Roman civilisations. Popular histories peter out at the collapse of the Western Roman Empire in the fifth century, and their coverage of the East tends to ignore or downplay Iran. Moreover, there is no oriental equivalent to Hollywood’s Ben Hur, Quo Vadis, and Cleopatra, the BBC series I, Claudius, or HBO’s Rome, which would help a Western audience imagine the ancient Iranian world (though it should be said that the new BBC series Art of Persia, hosted by Samira Ahmed, goes a long way to show that Iranian history is no less important and entertaining than its Roman counterpart).

From the 220s to 651, Iran was ruled by the Sasanian family. Its founder was Ardashir, a governor of Fars in south-western Iran, who rebelled and overthrew the incumbent Iranian king. He established the world’s first major confessional state. More than a century before the Roman empire became officially Christian, the Sasanian empire was Zoroastrian. Western Eurasia was divided between two mutually hostile states with incompatible faiths—a kind of fourth-century cold war. Both states claimed universal jurisdiction, and the Sasanian empire portrayed itself as the only legitimate authority on Earth.

Older scholarship presented the Sasanian state as a feeble, quasi-feudal, sparsely populated Asiatic despotism without a standing army, and which was no match for Rome. But this was wrong. Sasanian silver coinage and agriculture offer evidence of a well-run, centralised state. Unlike the Romans, who repeatedly debased their gold coinage, the Sasanians kept their silver drachmas at a quality level that hardly wavered over more than 400 years. Similarly, no Roman parallel can be found to the Sasanian state’s enormous investment in, and management of, agriculture and irrigation. The lowlands of Iraq were the most fertile lands in the world, and the state maintained a system of canals between the rivers Tigris and Euphrates to guarantee adequate irrigation. The wall across the plain of Gurgan (on the eastern side of the Caspian Sea) was the second largest in the world, putting Sasanian engineers almost on par with those of imperial China.

So it’s no surprise that the Sasanian state often was more than a match for Rome, and several Roman armies were destroyed in the wars provoked by the first two Sasanian kings. One Roman emperor, Valerian, was even captured (and supposedly skinned, taxidermied, and put on display in order to intimidate subsequent Roman embassies). After that, a state of war prevailed virtually uninterrupted until the Arab conquests in the seventh century, along an ill-defined frontier running south from the Caucasus down into northern Arabia. A sort of ancient Great Game took shape, with the principal victim being Armenia—an ancient kingdom, ethnically and culturally Iranian but with a growing Christian elite that exhibited Roman sympathies. The two powers refused to respect Armenia’s autonomy, and eventually settled on partitioning it between them. In practically every major conflict thereafter, Armenia served either as battleground or invasion route (roughly akin to Poland and Belgium in more recent times).

As time went on, the contest worsened and spread southward into Arabia and Ethiopia, with Iran and the Romans contesting control of the India trade that passed through the Red Sea. Unable to break the Persian monopoly, Justinian and his Byzantine successors tried to dominate the overland silk trade from China. This had disastrous consequences when the Turks, perhaps with Roman backing, aimed to disrupt the Persian system by flooding Iranian markets with endless rolls of cheap silk that rival Chinese dynasties had provided them as tribute. A long war resulted, in which Iran fought Roman and Turkish armies on multiple fronts.

Although Iran emerged victorious, the monarchy came under great strain, and a rebellion broke out. A high-ranking general claimed the throne, and the son of the former Sasanian king, Hormizd, fled to Roman territory, seeking an intervention against the usurper. The Romans obliged, and overthrew the rebel general. When, in turn, a rebellion broke out from within the Roman military, and the Byzantine emperor was overthrown, the Persian king saw his opportunity to invade and annex the Roman rump once and for all. That king was the aforementioned Khusro II, and the ensuing conflict was one of the most consequential in human history.

Siege of Constantinople in 626, as depicted on a mural at the Moldovița Monastery

The enormous war, fought from 602 to 628, was widely believed to be ushering in the end of the world. An impressive number of Jewish, Christian, and Zoroastrian apocalyptic prophecies survive from that period. The conflict was portrayed by both sides as a cosmic struggle between Christianity and Zoroastrianism, the outcome of which would bring on the last age before the coming of their respective saviours. There were many instances of destruction. But the Persian capture of Jerusalem in 614 stands out as an exemplary act of terror and violence, one that shook the Roman world to its foundations. The relics of the True Cross were captured and sent to Persia as a trophy of war.

Roman revenge came with the total destruction of one of Zoroastrianism’s most sacred fire temples in what is now Azerbaijan. The counterattack led by Heraclius had been spurred on by a novel doctrine of holy war, which Arab allies transmitted to countrymen in the south. Visions of the end of the world that appear in early portions of the Qur’an were influenced by the anxieties of this era. For his part, Muhammad cheered on the Roman side, and looked forward to their eventual victory (Qur’an 30: 1–5).

But Sasanian history is no mere chronicle of warfare with Rome. A spirit of co-operation took shape in the early fifth century, when Iran and Rome set aside their differences in the face of common enemies, including the Huns. The Sasanian state also adopted a policy of official toleration in regard to Christianity, and allowed the establishment of an indigenous church in imitation of the Roman model. (Sasanian kings also granted their Jewish subjects a wide degree of freedom, with the so-called Babylonian Talmud being created during this era.) Neither power relinquished claims to universal jurisdiction. But in diplomatic exchanges, the two powers acknowledged one another as partners in the struggle to restrain northern interlopers.

The nomads of Inner Asia posed a far greater threat to Iran than they did to Rome. Northern and eastern Iran abutted the Asiatic steppe directly, and there were few natural defences against invasion. Hence the massive Gurgan Wall and other fortifications in the Caucasus and Mesopotamia. Fighting along Iran’s eastern frontier was extraordinarily dangerous. Successive Sasanian kings were defeated by the Huns and forced to pay tribute. In 484, Persian king Peroz I was killed on campaign, and most of the Sasanian army was destroyed. This disastrous defeat provoked a crisis of succession and touched off more than a decade of unrest, during which time a renegade Zoroastrian priest named Mazdak (who preached common ownership of possessions—and women) became an influential figure. He eventually fell out of favour, and Khusro I had him executed in the late 520s. But Mazdakism lived on, and influenced Islamic mystical sects well into the Middle Ages. Soviet scholars, enamoured of Mazdak’s proto-communism, also took up the cause of Mazdakism, and tended to extol it above any other aspect of Iranian history.

The death of Mazdak, as depicted in the Shahnameh

To this day, the Sasanian Empire’s recovery in the sixth century under Khusro I and II is remembered as Iran’s ancient heyday. Reforms of the military, the tax system, and agriculture put the empire on a firmer footing. Public revenues increased and agricultural production peaked. A cultural programme sponsored by Khusro I seems to have included the creation of an official dynastic history of Iran—a document that is now lost, but which seems to have been recycled in later Persian and Arabic histories.

These improvements unfolded amidst grim circumstances. Warfare with Rome filled nearly the entire sixth century. And the 540s saw the outbreak of the worst pandemic in recorded history, one that seems to have been caused by the same bacterium responsible for the Black Death. Both Justinian and Khusro survived the plague after contracting it personally. But both their empires were weakened by the pandemic. These factors likely left them more vulnerable to the Arabs, whose lands seem to have been untouched by the plague.

The Arab conquerors must have been astounded at how quickly they were able to overthrow the last Sasanian king. Yazdgard III (r. 632–651) had to abandon Ctesiphon, near the modern site of Baghdad, and fled for his life into the Asiatic steppe. But he was intercepted and killed. His sons and a few surviving aristocrats managed to reach China, where the Tang emperor welcomed them to his court at Chang’an. There, a Sasanian court in exile lasted for almost 200 years, and a few abortive attempts at reconquering Iran were launched. Though there would never be an Iranian Justinian or Charlemagne to revive the Sasanian state, the memory of empire never perished.

Palace of Taq Kisra in the Sasanian capital of Ctesiphon, photographed in 1864

The Umayyad clan was the first Arabian dynasty to rule Iran. For nearly a century, it reigned from Damascus, attempting to enforce authority over the old Sasanian empire. Fifty-thousand Arabian troops stationed at the garrison city of Marv, in eastern Iran, took Persian wives and began adopting Iranian cultural practices. In 750, those troops rose in revolt and overthrew the Umayyads. The new dynasty, known to posterity as Abbasid, established their new capital in Baghdad, only about 20 miles from Ctesiphon.

Their civil administration imitated the customs of the Sasanian chancery, and a new generation of Iranian functionaries arose in service to the new empire, which took on an Iranian identity. The successors of Muhammad were instructed and edified by volumes of Persian literature, treatises on Iranian courtly manners, and the history of the Sasanians. The heritage of the Sasanian era—its literature, architecture, metal-working, glassware, carpets, and textiles—inspired subsequent mediaeval Persianate culture, and became part of the foundation of Classical Islamic civilisation.

Having written a book about the Sasanian empire, I’ve come to believe that there are two lessons that we can take from its history. The first is a startling reminder of the fragility of political systems and human institutions. In the early 620s, a Sasanian nobleman would have had every justification for great pride and confidence in his state. He would have expected the present order to go on forever, without being able to foresee that, in less than a generation, the entire Sasanian empire would be gone.

The second lesson is that, even amid total physical destruction, human culture and civilisation have astounding powers of regeneration. Iranian civilisation survived the collapse of the Sasanian state, and returned as the main impetus behind the Islamic golden age. Despite the uncertainties and tensions that characterize modern political life, we would do well to remember that the future we want is never the future we actually get, and that civilisation will outlast the fragility of politics.

I wrote The Last Empire of Iran to tell the story of the Sasanian dynasty from beginning to end. It is a narrative that covers some of the most important events of human history. And over the past 1,400 years, the story has lost none of its power.

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Michael Bonner

Michael Jackson Bonner is a Canadian political adviser, a historian of Iran, and a contributing editor to Dorchester Review.