Religion in the Sassanid Empire

The Sasanian, or Sassanid, dynasty ruled from 224 to 651 CE, with its court centered at Ctesiphon on the Tigris in Mesopotamia and its power extending across much of the Iranian plateau. Kings publicly identified themselves as Mazda worshippers, linking royal identity to Zoroastrianism; Christians, Jews, Manichaeans and other communities also lived under their rule. Their communities maintained distinct institutions and negotiated their relationships with the court in different ways.

On this page5 sections

Royal patronage and Zoroastrian institutions

Sasanian kings presented themselves as Mazda worshippers. Their coins displayed a fire altar on the reverse, placing a sacred symbol in everyday transactions. At the Ka’ba-ye Zartosht monument in Fars, southwestern Iran, King Shapur I’s inscription names fires established for himself and members of his family. It also assigns daily supplies of a lamb, bread and wine to those fires and their commemorative rites. Such provisions joined royal land and goods to recurring religious service.

Priests held authority over ritual, religious property and learned traditions. Kartir, a senior priest who rose under Shapur and later kings, says in his own inscriptions that he was entrusted with religious documents and endowment deeds, records that assigned property or its income to religious support, and eventually served as a judge. He also boasts of acting against rival communities. His inscription names Jews, Buddhists, Brahmans (Indian religious specialists), Mandaeans (a Mesopotamian baptizing community), Christians and Manichaeans among groups he said were “smitten.” The inscription presents these as Kartir’s own campaigns; his claim to have punished priests who disagreed with him shows that religious authority was contested even within the Zoroastrian clergy. The royal faith shaped institutions, while the reach and influence of particular priests changed over time.

Zoroastrian teaching described a struggle between the wise lord Ahura Mazda and the destructive spirit Angra Mainyu, called Ahriman in Middle Persian. People’s choices mattered within this conflict: truthful speech and good actions supported the good creation. Priests maintained sacred fires and interpreted religious teaching. The Avesta, the collection of Zoroastrian sacred texts in Avestan, an Old Iranian language, was taught through careful recitation and memorization. Its Middle Persian Zand provided translation and commentary. During Sasanian rule, priests and political authorities helped collect the Avesta into a recognized written collection, while memorized teaching remained part of priestly training.

Christian bishops and royal diplomacy

Christian communities were established across Mesopotamia and Iranian lands before the Sasanian period. By the early third century, sources named bishops from northern Mesopotamia south toward Susiana and the Persian Gulf. In 410, with King Yazdegerd I’s permission, the bishops met in a synod, or council, at Seleucia-Ctesiphon, the paired royal capital on the Tigris. They adopted the Nicene Creed, a statement of Christian belief agreed at Nicaea in 325, and church canons, or rules, that regulated clergy and congregations. Their list of six jurisdictions included Iranian provinces as well as Mesopotamian districts.

At a synod in 424, the Church of Persia under its catholicos, or senior bishop, had become largely independent of the older western jurisdictions. Metropolitans coordinated groups of church districts through the hierarchy of the Church of the East, while Armenian Christians kept a separate hierarchy.

Royal policy could protect churches and later turn against them. Bishop Marutha, an envoy from the Eastern Roman Empire, won Yazdegerd’s confidence and helped arrange the 410 meeting. The king allowed Christians to worship publicly, rebuild damaged churches and travel within their church districts. Near the end of his reign, however, Yazdegerd ordered persecution, with Christian and later accounts citing conflicts over the destruction of fire temples and other disputes. Under Shapur II, long wars with Rome sharpened royal suspicion that Christians might support the rival empire. Clergy and congregations therefore negotiated their position under rulers whose policies shifted with court politics and international conflict.

Jewish leadership and the Babylonian Talmud

Jewish communities had lived in Babylonia, southern Mesopotamia, for centuries before the Sasanians came to power. During Sasanian rule, rabbis in the region developed the Babylonian Talmud, a large collection of discussions about Jewish law, ritual and daily conduct. Its formation is usually dated from about 220 to 500 CE. The discussions also reflect contact with surrounding Persian society: rabbis addressed questions such as good and evil, the transmission of teaching and life after death, sometimes debating Zoroastrian priests and Manichaeans.

The Iranian government recognized the exilarch, head of the Babylonian Jewish community, as its representative. Rabbis taught and debated religious law, giving communal representation and scholarly teaching distinct roles.

Mani, Mazdak and contested teachings

Mani began preaching in Babylonia around 240 CE. Manichaeism taught that Light and Darkness were two primordial and independent powers. In this account, particles of Light became trapped in the material world, and people could help release them through knowledge and disciplined religious practice. Manichaeans distinguished the Elect, who followed strict abstentions including avoiding meat, wine and harm to plants, from Hearers, who prepared food and supported their religious work. Mani wrote in Syriac, a form of Aramaic, and prepared a book in Middle Persian, the Sasanian court’s Iranian language, for Shapur: the Šābuhragān. Shapur retained Mani in his retinue for a time and granted him privileges that allowed the movement to spread. Under Bahram I, the high priest Kartir pressed against the movement; Mani was imprisoned and died in confinement. Missionaries carried Manichaean texts into several languages and across the empire’s borders.

A different dispute arose under Kavad I in the late fifth and early sixth centuries. Later accounts associate Mazdak and his followers with changes to ritual offerings and claims about sharing property and family relationships. Some scholarship interprets the movement as redirecting sacrificial offerings toward poor and hungry people, reducing the priests’ share. Other accounts accuse followers of holding wives, children and possessions in common. Because the surviving narratives were written by opponents or much later compilers, these descriptions do not settle exactly what the movement taught or how widely its practices spread.

Eastern regions and religious life at home

Farther east, Bactria and nearby regions had Buddhist communities connected to routes toward Central Asia and India. Sasanian control in these areas changed over time, so the evidence describes frontier contact rather than Buddhist practice throughout the empire. Kartir’s inscription names Buddhists among groups he claimed to have attacked, while regional evidence places Buddhist communities mainly in the east.

Household ritual offers another view of this variety. From central and southern Mesopotamia, archaeologists have recovered inscribed earthenware incantation bowls, made mainly between the third and seventh centuries. A practitioner wrote a protective spell on the inside of a bowl, sometimes in a spiral. The formulas sought help against illness, childbirth difficulties, poverty and other misfortunes; some directly command a spirit to leave a named household. Bowl texts appear in Jewish, Mandaean and Syriac scripts, among others; their shared formats and borrowed formulas show that religious ideas circulated across community lines in daily life. Religious practice required material support, from a temple’s endowed provisions to objects used in a household.