Ancient Persian civilization saw the rise of one of the great monotheistic religions of world history, Zoroastrianism, while the culture of ancient Persia was a rich fusion of many elements.
Traditional Iranian religion was undoubtedly polytheistic, worshipping a pantheon of gods and goddesses, as were most religions of the day. At some time, however - which most scholars think was in the 6th centuiry BC - a prophet called Zoroaster began preaching a monotheistic religion, calling for people to follow only the supreme God, Ahura Mazda.
Zoroaster taught that Ahura Mazda is the creator of both the material and spiritual worlds, and is the God of all that is good. To be a true follower of Ahura Mazda, one must live a righteous life. However, Ahura Mazda is opposed by an evil being, the “Father of Lies”, Ahriman. People have to choose between serving Ahriman or Ahura Mazda, the “Wise Lord”. These two are in a constant struggle for the souls of humans; but in the end, Ahura Mazda will prevail and his servants will live.
Where Zoroaster got his ideas from – if indeed they did not originate in his own spiritual experience – is unknown. One element which Zoroaster seems to have taken over from the existing Iranian religion was the central importance of rituals involving fire. In Zoroastrianism, this was not fire worship, but rather a reverence for fire as the ultimate symbol of purity.
The religion he founded, Zoroastrianism, seems to have spread steadily amongst the Iranians, but how influential it was at different times, at least before the Sasanian period, is hard to say. According to the Greek historian Herodotus Iranian society in the 6th century, under the Medes, had a group of hereditary priests (he called them a tribe) called magi; and several centuries later we find Zoroastrian priests being given the same label. However, it is probable that Zoroastrians borrowed the term for priest from their parent culture, and that the magi of the 6th century were the guardians of traditional Iranian religion. They may have been similar to the hereditary priestly caste of Brahmins in Indian Aryan society. This certainly fits with the conservatism they apparently clung to in opposing the innovations in Persian government and culture under the early Achaemenids.
Religious policy under the Achaemenid empire
The Achaemenid kings’ religious policy was characterized by tolerance towards their subject peoples’ beliefs and practices. The most famous instance of this is their dealings with the Jewish exiles who they found in Babylon and other Mesopotamian cities after their conquest of that region. Cyrus allowed them to return to Jerusalem and rebuild their temple. Darius funded the restoration of the Jewish temple; and Artexerxes I sent the Jewish priest Ezra to Jerusalem to reintroduce temple worship and the old Mosaic Law back into Jewish life. Later he sent a Jew who had risen high in his service, Nehemiah, to enhance the security of the people of Jerusalem by rebuilding the walls of the city.
Darius made sure that his officials respected the religious practices of his subjects, as is shown in a letter to his official, Gadatas, ordering him to restore a Greek sanctuary. When in Egypt both Cambyses and Darius were careful to observe traditional Egyptian rites related to kingship.
Whether or not the Achaemenid kings were themselves Zoroastrians is a matter for debate. Darius I and later Achaemenid kings acknowledged their devotion to Ahura Mazda in inscriptions, but devotion to Ahura Mazda was (at the time) not necessarily an indication of an adherence to Zoroaster's teaching. It does seem, however, that the Achaemenid kings were strongly influenced by Zoroastrian teachings. The tone of their official inscriptions reflects a concern for righteousness; and what look like the remains of fire altars have been found in the royal city of Persepolis.
Religious policy under the Sasanian empire
The tolerant religious policies of the Achaemenid kings continued under the Parthians. Under the Sasanians, however, a more robust nationalism led to Zoroastrianism becoming a national church. This sometimes made life difficult for members of other faiths.
The Sasanian family had close links with Zoroastrianism long before it became the ruling family of a great empire: Ardashir’s grandfather was reputedly a Zoroastrian priest. Unsurprisingly the profile of the religion was greatly enhanced with the Sasanian rise to power, but it was some time before it became the organized state church of the empire. This happened in response to various developments.
The first of these was the spread of a heterodox sect called Manichaeism (see below), which spread very quickly, even winning adherents amongst the nobility and high officials. This prompted the Zoroastrian high priest to seek royal support in eliminating the sect.
The second factor in Zoroastrianism’s rise to be an organized national church was the conversion of the Roman emperor Constantine to Christianity - and in particular his claim to be the protector of Christians everywhere. Suddenly the Christians in the Sasanian empire found themselves being viewed by officialdom as a potential fifth column, their loyalty to their rulers fatally undermined by their faith.
It was this development which elevated Zoroastrianism to the status of an official religion. It came to be established as an hierarchical organization on similar lines to the Christian church in the Roman empire, with clergy organized in ranks, with the village priest, tending the local fire temple, forming the base. There is some evidence that local clergy also used their skills in reading and writing to act as scribes, registrars, legal advisors and schoolteachers. The Zoroastrian church had its own courts, enforced its beliefs on the people and presided over bouts of official persecution of non-Zoroastrians, above all Christians and Jews. It was probably at this time that the Avesta, the sacred writings of the Zorostrians, was compiled, though much of it was clearly composed long before, even as early as the Achaemenid empire.
At court, the Zoroastrian high priests had huge influence. They acquired a decisive influence in the choice of new kings; the monarchs reciprocated by taking an active interest in Zoroastrian theology, and just as the Roman emperors helped shape Christianity, the Sasanian kings had an influence on how their religion developed. Rituals became more elaborate, and an increased emphasis on purity gave the fire altars a more central role. Unsurprisingly the Zoroastrian church became more rigidly doctrinaire, more legalistic, less tolerant of varying ideas. For example, a school of thought had grown up in early Sasanian times which taught that both Ahura Mazda and Angra Mainyu had emanated from an original principle of infinite time. In the 6th century, however, this teaching was declared heretical, and suppressed.
The Achaemenids and the Parthians were, as we have seen, tolerant in matters of religion, and the Jews prospered under both empires: apart from reestablishing their homeland with official encouragement under the Achaemenids, settlements of Jews spread far and wide across the Persian empire, and, although persecuted in Judaea for a time under the Seleucids, they flourished again under the Parthians.
Christianity arrived early in the Parthian empire, within the first generation after the religion’s founding. It thrived, and by the 3rd century AD there were almost certainly more Christians under Parthian rule than under the Romans.
Both Judaism and Christianity were particularly at home within the cities. The same was true for Buddhism, which came in from the east from the 2nd century BC. This faith was particularly successful in attracting converts at the highest levels of society, even within the royal family: a Parthian prince was amongst the first Buddhist missionaries to China.
The religious picture was more complex under the Sasanians. The early Sasanian kings’ spectacular victories against the Romans had the effect of strengthening Christianity within the Sasanian empire, because many of the people deported from Antioch and other cities in the Roman province of Syria seem to have been Christians.
The increasing popularity of Christianity may have hastened the rise of Zoroastrianism as the official religion of the Sasanian state, and from that time Jews, Christians and Buddhists experienced bouts of persecution. Buddhism indeed seems to have disappeared as a popular religion within the Sasanian empire.
For Christians, as we have seen, their experience of persecution intensified after the Roman emperor Constantine became a Christian. Even so, apart from times in the 4th century they were allowed to follow their own religious practices and beliefs more or less in peace. They had their own officially recognized courts to deal with communal disputes according to their own customs. Members of the Sasanian nobility, and of the royal family, became Christians. At the end of the Sasanian period there were substantial communities of Christian and Jews in most towns and cities of the Middle East.
During the mid-3rd century a man called Mani started preaching a new creed. This was an amalgam of ideas taken from various religions, chiefly Christianity, Zoroastrianism and Buddhism. Mani claimed to be the last and greatest Apostle of Jesus, and, putting a metaphysical interpretation on the Christian gospel, attempted to combine it with the teachings of Zoroaster to create a new universal religion.
Mani’s teachings seem to have taken wing, and began to spread far and wide. Prominent members of the Sasanian royal family became converts. The Zoroastrian clergy, however, vigorously opposed Mani and his teachings, and In 274 they were able to have him executed. His followers were persecuted too, and the new religion was driven from the empire. Manichaeism continued to spread in India, central Asia and the Roman empire.
Mithraism was a religion which, although not practiced in the lands ruled by Iranian dynasties (so far as we can tell) had its roots in the ancient Iranian religion. The god Mithras (or Mitra) was an Iranian-Indian deity who, for some obscure reason, became the object of worship amongst a section of Roman society, especially in the army. It would be one of the chief competitors to Christianity, and probably had some influence upon this religion.
The literature, art and architecture of the Achaemenid empire is essentially that of its constituent peoples. In Babylonia, for example, traditional Mesopotamian temples and ziggurats were constructed and refurbished, and temple life went on much as before. In fact, the Achaemenid period saw Babylonian astronomy continue to develop, with new observations being made and calculations refined. In Egypt, temples and statues continued to be erected in the age-old style, and official and priestly texts stood firmly in their ancient tradition. The newly rebuilt temple in Jerusalem was designed to resemble its predecessor which had been destroyed by Nebuchadnezzar’s army, and the Jews committed much of their scriptures to writing at this time. The Greek cities of Asia Minor participated fully in the cultural developments taking place on the Greek mainland at that time; they produced eminent thinkers such as Heraclitus of Ephesus, who was a major figure in the advancement of Greek philosophy.
Nevertheless there was a distinctive Persian art and architecture which appeared under the Achaemenids. This was an imperial art which was embodied in the magnificent palaces, royal tombs and rock reliefs which the kings ordered to be constructed in their capitals at Pasargadae, Susa and Persepolis. It was solemn and dignified, designed to awe visitors by displaying the mighty power of the Achaemenid kings.
Culturally, the Persians owed a huge debt to the Elamites, and through them, to the Babylonians, Assyrians and Sumerians. The early Achaemenid kings used Elamite as their main language of government, drew on the administrative expertise of the old Elamite administrative elite based in Susa. The connection they felt towards Elamite culture is reflected in the fact that Elamite was one of the three scripts used in official and ceremonial documents (the others being Old Persian and Akkadian). Persian styles in art and architecture largely followed Mesopotamian models, though with modifications of their own.
A cultural mix
As well as their great debt to Mesopotamian antecedants, incorporated elements of their own. This can be seen most clearly in architecture, where the traditional many-pillared halls of Iranian kings and chiefs was reproduced on a grand scale in the imperial palaces of Susa and Persepolis, but now built in stone and decorated by Greek, Egyptian and other foreign artists using their own aesthetic sensibilities. From this time dates the distinctively Persian tradition of taking foreign influences, mixing them with native traditions and working them into something new.
The Seleucid period saw Greek influences predominate. Greek-style towns appeared all Mesopotamia and Iran, and eastward into Afghanistan. Nevertheless, local practices continued in places: the Iranian tradition of monumental rock carvings continued, though now frequently showing Greek-style gods wearing Greek style clothing.
In taking over lands previously ruled by the Seleucids, the Parthians were taking control of numerous Hellenistic cities housing an international Greek-speaking civilization. The Parthian kings did nothing to suppress this civilization, but rather promoted it. They themselves became Hellenistic in their ways, and patronized Greek art, architecture and literature. Greek plays were put on at their court.
These policies alienated the Iranian aristocracy, and in time an aristocratic-sponsored reaction set in. Greek language and culture lost ground in Iran, and from the 1st century AD Iranian elements became more dominant. Under the Sasanian regime the Iranian revival in art and architecture strengthened. Greco-Roman influences had become too embedded in the culture of the region to be eradicated, however, and their influence remained strong. Greek techniques in sculpture, architecture and metalwork continued to be used, and statues, paintings and jewellery continued to depict Greek mythological scenes. These mingled with ancient Mesopotamian, Iranian and other elements to create the distinctive styles of the ancient Persian civilization which came to maturity in the Sasanian period.
The early Achaemenid kings, Cyrus, Darius, Xerxes and Artexerxes I, were prolific builders, and it is no surprise that Achaemenid architecture is seen most clearly in their royal palaces in Susa and Persepolis.
The design of the palaces and the sculptural reliefs which adorned them were essentially based on Babylonian and Assyrian forms, which themselves were the culmination of thousands of years of Mesopotamian stylistic evolution. However, the Persians builders added elements of their own. For example, the palace-complexes tended to rest on massive terraced platforms, sometimes excavated into hillsides, a feature not found in traditional Mesopotamian design.
Another important element was the many-pillared audience halls, which probably derived from the wooden halls of Iranian kings and chiefs but was reproduced in stone on a grand scale in the imperial palaces of Susa and Persepolis.
So too from Parthian and Sasanian times, it is the remains of royal palaces such as the ones at Firuzabad and Bishapur, both in Fars province, and in Ctesiphon, in Mesopotamia, which tell us most about their architecture. A design feature which survived from Achaemenid times into later Persian periods was the massive terraced platform, on which several Parthian and Sasanian palaces were built. In other respects, however, Iranian architecture went through great changes.
The first of these, under the Seleucid dynasty from Macedonia, was the widespread introduction of Greek architecture across Iran and Mesopotamia. Then, during the Parthian a distinctively “Iranian” architecture developed in the region. Its most characteristic feature was the rectangular, barrel-vaulted hall open to a courtyard, which in effect turned the hall into a deep-recessed high-arched portico.
This seems to have had local Iranian roots - some observers are reminded of the tents of nomadic chieftains in northern and eastern Iran, the milieux from which the Parthians originally sprang. The replacement of Greek-style columns and beams with open vaults gave Iranian buildings a dramatically different visual impact to those which had come before, and formed the basis for developments which would endure throughout the Islamic period to the present day.
Under the Sasanians, Iranian architecture was further developed with the introduction of the dome. In its early stage this was in fact a fairly well-rounded octagon; later, Iranian architects draw nearer to the perfection of a complete circle, though it would have to wait until Islamic times for this to be fully achieved. The development of the dome further enhanced the beauty and dramatic quality of Iranian buildings.
The elements which had been so prominent in the Greek architecture of the Hellenistic period - columns, capitals, cornices and so on - survived as decorative features on facades, with no constructional purpose. They served to break up solid walls.
In terms of religious buildings, the remains of numerous fire temples, places of Zoroastrian worship, have survived from the Sasanian period, and some from the previous Parthian period. These are square buildings roofed by a dome over four arches, and surrounded by cloisters and chapels.
The fact that the Achaemenid palaces were constructed by teams of skilled craftsmen drawn from all over a multinational empire resulted in divers artistic elements being introduced, from widely varying traditions. The result was a unique fusion: the formal style of Babylonian figurative design was modified with a more human, more fluid quality, imported by Greek sculptors, and the slender columns in the audience halls displayed Egyptian and Greek motifs. Stylistic elements from Lydia (in Asia Minor) and Urartu (in Armenia) can also be detected.
To the northwest of Persepolis are four majestic tombs of Achaemenid kings. These are carved into a rock face in the Zagros mountains, to exactly the same design. Their huge (22 metres high) fronts depict the sculptured facade of a palace with tall columns, above which the kings are shown before a fire altar. They stand on platforms supported by the representatives of the thirty nations belonging to the empire. Their overall design may have come from Urartu (in modern Armenia) or Lydia (in modern Turkey).
One final piece of Achaemenid art must be mentioned, the great relief and inscription which Darius the Great had carved into the rock face at Behistun, high above the road that passes through the Zagros mountains from Babylon to Ecbatana, to celebrate his victories. This monumental relief started a long tradition of rock carvings by Iranian kings and nobles.
Large numbers of beautiful small objects have survived from Achaemenid times: metal tableware (vessels, plates, cult utensils) in gold and silver, jewellery (earrings, bracelets), weapons (daggers), seals and gems cut in the old Mesopotamian manner but with Iranian figures.
One cultural feature, which the Persians inherited from previous Mesopotamian cultures and spread around their empire, was landscaped gardening. The Assyrians had laid out extensive parks and gardens around their royal palaces, and the famous "Hanging Gardens" of Babylon were probably just such an artefact. In the Persian period, such pleasure grounds were created around their empire. The Greek word for them was the same as our word “paradise”, which aptly sums up their role as places of beauty and relaxation. They were designed to enable Persian kings and nobles could take their ease. This feature of Persian culture persisted into later times - around his magnificent palace in Ctesiphon the Sasanian king Kosrow II’s created brilliant landscaped gardens,and parks containing thousands of wild and domestic animals - and on into the Islamic period.
Parthian art was characterized by a certain formalism, even rigidity. This was enhanced by the prevalence of figures being presented from the front rather than the side. Statues show great detail in clothing and adornment. The art of the period was also characterized by a willingness to borrow styles and motifs from Greek and Mesopotamian cultures, and to recombine them in new ways. Many scenes show Greek deities and mythological beings in Greek garb (if not nude); others show figures in Parthian dress, some highly elaborate, some quite plain, and Iranain mythological beasts also appear.
Rock reliefs, which had been a major royal art form in Achaemenid times, continued into the Seleucid, Parthian and Sasanian periods. They depict Greek heroes such as Heracles (who seems to have been popular amongst the Parthians), kings and nobles in Greek dress, and kings and nobles in Parthian dress (trousers, tunics) - sometimes the two different modes of dress appear in the same scene. The figures are worshiping, being enthroned, paying homage to royalty or nobility, or hunting. Some images are in relief, some in the round.
In Sasanian times rock carving functioned more as royal propaganda. It was on a more monumental scale then under the Parthians, and tended to focus on victories in war, royal investitures or hunting scenes. Most were carved within the Sasanian base of Fars, The most famous relief of all, possibly the best-known piece of ancient Iranian art, shows the humiliation of the Roman emperor Valerian by the Persian king Shapur I.
Colourful stucco decorated both the interiors and exteriors of Parthian and Sasanian palaces and mansions. Surviving examples include what must have been lavish decorations with animal, floral and geometric designs. Writers refer to paintings and murals adorning the palace walls.
Sasanian artists and craftsmen were experts in making fine silverware. Many feature lively scenes of dancers, satyrs and maenads, surrounded by grapes and vines, and other scenes from Greek mythology. Later, royal iconography came to the fore, with the king-as-hunter a standard motif.
Sasanian luxury arts also include seals made from precious and semi-precious stones, and glass and ceramic vessels. Beautiful Persian textiles - silks, tapestries, carpets and rugs - were in high demand in other lands. Through trade and diplomatic exchange, many such examples spread far beyond the borders of the Sasanian empire, to Europe, India and China. The influence of ancient Persian art is discernible in the art of medieval Europe, central Asia, and China, and of course the Islamic Middle East long after the fall of the Sasanian dynasty.
Before Achaemenid times, Iranian culture was a non-literate one. The exception here, as with so much else about pre-Achaemenid Iran, was Elam, which had developed literacy more than two thousands years before. Literacy had never spread to the farming and pastoral peoples in the rest of Iran.
There was, however, a rich oral tradition. Above all, a collection of songs, hymns, prayers and other religious works known as the Avesta were developed over many centuries - indeed had been developing before the Iranians entered Iran, and probably share a common ancestry in the deeps of time with the oral tradition which would give rise to the Vedas, in the Indian subcontinent. The archaic version of Iranian in which it was composed is known as Avestan.
The first committal of an Iranian language to writing occurred in the early Achaemenid period, when Darius wanted to commemorate his victories over his enemies. He commissioned a group of scribes to develop a script for the Persian language, which modern scholars call “Old Persian”. His monumental inscription at Behustan contains the first example of this (it was also written in Babylonian and Elamite, and like them used a cuneiform script). Monumental inscriptions of the Achaemenid period continued to use Old Persian, and recent archaeological finds at Persepolis show that it was used to some extent in administration. It is also found on clay tablets and seals.
Old Persian was used primarily for official and prestige purposes, and never came into common use. In the early days of the Achaemenid empire government scribes normally worked in Elamite, using its cuneiform script. Soon, however, Aramaic, which the Assyrians had used before them, had established itself as the language of choice for administrators. This was due to its prevalence throughout the territories of the empire and also to its alphabetic script, which made it so much easier to use than cuneiform.
The spread of urban centres in Iran in Achaemenid times would have been accompanied by spreading literacy, especially amongst scribes and traders. This would have been based on Aramaic. So prevalent did the Aramaic script become that it had soon been passed to the Indian kingdoms further east, where it became the basis for various scripts such as Sanskrit. The Aramaic language also strongly influenced spoken Persian, so that the language underwent a major change; and when an Iranian language again became committed to writing, it was based on Aramaic.
This language was Parthian. In the intervening period, since the fall of the Achaemenid empire, Iran had been ruled by the Seleucid kings, who had taken control over the eastern conquests of Alexander the Great. Under them, Greek had become the language of government, commerce and culture. With the rise of the Parthians, this situation hardly changed. During the first 150 years of the Parthian empire, the royal court was a major centre of Hellenistic culture. This included a deep acquaintance with Greek literature. It is said of the Parthian king Orodes that it was whilst watching a Greek play that news of the great victory over the Romans at Carrhae (53 BC) arrived.
This aspect of court culture began to become less important in the 1st century AD as the Parthian ruling class turned increasingly to Iranian culture as its preferred mode of expression. Nevertheless, the fact that the Parthian empire contained a large Greek-speaking population meant that the Greek language continued to be used in official inscriptions, and presumably other official documents, for some time. Parthian and Middle Persian gradually become more important, however, and Greek vanished from official inscriptions in early Sasanian times.
In fact, only a few, short texts dating from the Parthian era have survived, all of a purely administrative nature. They are enough to show us that the Parthian script was an alphabetical writing system based on Aramaic. However, a rich body of oral works was clearly composed in Parthian. This is evident from epics, romances and wisdom writings which were committed to writing many centuries later, and which contain many Parthian words and phrases.
Moreover, the Parthian language continued to be extensively used under the early Sasanian monarchs, and some longer inscriptions have survived from that time. These are mainly fragmentary religious works of the Manichaean faith (see above), which sprang up in early Sasanid times.
Under the Sasanians, the dialect of their home province of Fars came to predominate, at east at court, and the literature that was written in this dialect is known as Middle Persian. This was the language of royal monuments, with important inscriptions dating from the earliest phases of the Sasanian empire. The famous the trilingual inscription of Saphur I (241-72) which boasts of his exploits against the Romans was written in Middle Persian, Parthian and Greek.
Middle Persian was the language of the Zoroastrian church, and many surviving texts are of a religious and liturgical nature. Most notably, the Avesta was written down in Sasanian times, accompanied by a commentary, and this Middle Persian version became the standard for later generations.
The Manichaean church also used Middle Persian, with texts comprising prayers, hymns and religious polemics.
The outstanding secular work of the Sasanian period is The Deeds of Ardashir, which became the basis of the national Iranian epic, the Shahnameh. The Deeds of Ardashir is probably the sole surviving example of numerous historical annals. Foreign prose works were also translated; among them, including Hellenistic romance literature and Indian books of tales. Sasanian kings such as Kosrow I were familiar with Greek philosophy, and collected books of all the faiths and schools of thought that he knew about. He patronized scholarship and learning, sponsoring the translation of works on science, medicine and astronomy from Greek and Indian originals into Persian. It was probably at this time that the Indian concept of decimal numbers and the use of zero as a place marker came into Persian mathematics.
At a more mundane level one lengthy legal work has survived, the Book of a Thousand Judgements.This must represent the sole survivor of a mass of legal texts. It discusses a number of actual or hypothetical cases concerning marriage, inheritance, property, rents, trade and so on. Other secular works which have survived are a couple of gazetteers, Cities of Iran and Wonders and remarkable features of Sistan; a couple of instructional works, The explanation of chess and Husraw, son of Kawad, and a page, which gives a vivid picture of life at the court of a Sasanian king; and a political treaties written in Sasanian times but later translated into Arabic, Testament of Ardasir. and a Persian translation (the Letter of Tansar).
These must be just a few survivals from a wealth of written works. Much Sasanian literature was probably lost in the great upheavals which came later, for example the Arab conquest of the 7th century and the Mongol conquest of the 13th century, both of which resulted in great destruction for the cities of Iran. The majority of Sasanian literature, however, probably fell out of use as Middle Persian was gradually replaced by Arabic. It is likely that much of this literature does indeed survive, in Arabic works that are either direct translations of lost Sasanian works, or were inspired by them.
An account of Iranian literature at the time of the Sasanian empire would not be complete without a brief comment of writings by non-Persian but Iranian peoples, most of whom would have been subjects of the Sasanian kings. Writings from Bactria, Sogdia and Chorasmia (all provinces within the Sasanian empire at some time) and Khotan (an Iranian-speaking Buddhist kingdom in central Asia) have also survived. These tend to take the form of workaday items such as letters, lists, accounts, legal documents, seal inscriptions and coin legends. They also include many religious texts, of Buddhist, Manichaean and Christian derivation, and fragments of medical texts, translated from Syriac and Indian originals. A collection of Sogdian correspondence has been discovered in western China, and Sogdian rock inscriptions have appeared in Mongolia. These show the far-flung trading connections which the Sogdian merchant community maintained across central Asia.
What seems clear is that the Sasanian period saw a flowering of scholarship, covering philosophy, religion, science and medicine. Scholars fleeing religious persecution in the Roman empire, at different times both pagan and Christian, found refuge within the borders of the Sasanian empire and continued working under the patronage of the Persian kings. Greek and Syriac works were translated into Persian, and in medicine, in particular, knowledge from Greece, Persia and India seems to have mingled. Also, as we have seen, it is probably in later Sasanian times that Indian mathematical concepts of zero and the decimal system came to Persia.
Centres of learning such as Nisibis (staffed by Nestorian scholars who had fled persecution in the Roman empire) and Gundishapur, became important locations for the study of philosophy, science, mathematics and medicine. They were in fact proto-universities, or indeed research institutes. They formed models for the later “House of Wisdom” which would flourish in Baghdad in Islamic times.
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