Sasanian Empire
The last great pre-Islamic Persian empire, which made Zoroastrianism a state church and rivalled Rome for four centuries.
224–651 CE
The Iranian plateau and Mesopotamia, from the Euphrates to Central Asia, with a capital at Ctesiphon
Economy
The Sasanian economy drew its wealth from the intensively irrigated farmland of the Sawad in Mesopotamia, whose canal networks made lower Iraq the empire's richest tax base. Khosrow I's fiscal reform in the sixth century replaced arbitrary crop-sharing with a fixed land tax (kharaj) assessed by survey and a graduated poll tax, stabilising revenue and strengthening central authority. Silver drachms of high, consistent purity funded the state, and royal control of key crafts and long-distance trade routes concentrated resources at the court.
Law
Sasanian law was inseparable from the Zoroastrian religion, administered by mobeds (Zoroastrian judges) who applied norms rooted in religious tradition, later compiled in the Middle Persian legal book Mādayān ī Hazār Dādestān ('Book of a Thousand Judgements'). Society was formally stratified into estates—priests, warriors, scribes, and commoners—and law upheld this hierarchy alongside distinctive Zoroastrian family and property rules. The king of kings stood as ultimate arbiter, and the fusion of throne and altar meant that religious orthodoxy and legal order reinforced each other.
Education
Learning centred on the Zoroastrian priesthood, which transmitted the Avesta and its Middle Persian commentary (Zand) largely by oral memorisation before it was committed to writing. The famed academy of Gondishapur became a great centre of medicine and scholarship, where Greek, Syriac, and Indian learning was gathered, translated, and taught, especially after Khosrow I welcomed displaced philosophers. This tradition of translation and inquiry passed into the early Islamic world, seeding the later House of Wisdom in Baghdad.
Army
The Sasanian army's decisive arm was the armoured cataphract cavalry, elite noble horsemen (savaran) encased in mail and mounted on barded horses, supported by war elephants and levied infantry. Under Khosrow I military reforms reorganised the command into four regional divisions and broadened recruitment of a salaried cavalry drawn from the lesser nobility (dehqans). For four centuries these forces fought Rome and Byzantium across Mesopotamia and Armenia, and their heavy cavalry tactics deeply influenced both Roman and later Islamic warfare before the exhausted empire fell to the Arab conquest at Qadisiyya and Nahavand.
Religion
The Sasanians made Zoroastrianism a state religion, elevating the priesthood under the powerful mobed Kartir and maintaining sacred fire temples such as the great fire of Adur Gushnasp. The dualist faith of Ahura Mazda and Angra Mainyu structured cosmology and morality, while the state periodically persecuted rivals—Christians, Jews, and the syncretic movements of Mani (Manichaeism) and the radical reformer Mazdak. Yet large Christian and Jewish communities persisted, and the Babylonian Talmud was compiled under Sasanian rule, testifying to a plural society governed by a Zoroastrian establishment.
Architecture
Sasanian architecture is famous for the monumental brick vault, above all the soaring parabolic iwan of the Taq Kasra at Ctesiphon, long the largest unreinforced brick arch in the world. Builders mastered the squinch, which allowed round domes to rest on square chambers—a technique that profoundly shaped later Islamic architecture. Grand palaces at Firuzabad and Bishapur, rock reliefs celebrating royal victories, and fire-temple complexes projected the majesty of the king of kings across the Iranian landscape.
Trade
Straddling the routes between the Mediterranean, India, and China, the Sasanians were the great intermediaries of the Silk Road, controlling the flow of Chinese silk westward and levying profits on caravan and maritime trade through the Persian Gulf. Their merchants and the closely tied Sogdians dominated overland commerce in luxury goods, and Sasanian silver vessels and coins have been found from China to Scandinavia. Rivalry with Byzantium was partly a struggle over these trade routes, prompting both empires to seek alternative paths for the lucrative silk supply.
Technology
Sasanian technology excelled in hydraulic engineering: vast qanat systems and monumental works like the Band-e Kaisar bridge-dam at Shushtar, built partly by captured Roman labour, irrigated the plateau and lowlands. Persian metallurgy and glassmaking were prized across Eurasia, and the empire preserved and translated Greek and Indian science in medicine, astronomy, and mathematics at Gondishapur. This inheritance—administrative, agricultural, and scientific—was absorbed almost wholesale by the caliphates, giving the technical foundations of the early Islamic golden age a deeply Sasanian character.