What religions were practiced in Iraq during the Sasanian Empire?

During the Sasanian Empire, the region now known as Iraq experienced significant religious pluralism, characterized by the coexistence of several major faiths alongside older local traditions.12

• Zoroastrianism: This was the official state religion of the Sasanian Empire. While it was primarily practiced by the Persian ruling class and administrative elite, it was supported by a formal ecclesiastical hierarchy that exerted significant influence over state affairs.132
• Christianity: A large portion of the population, particularly in the north, were Christians. They were divided into two main groups: the Nestorians (linked to the Church of the East), who were generally tolerated due to their opposition to the Roman Empire's church, and the miaphysites (linked to the Jacobite church), who faced more suspicion and occasional persecution.21
• Judaism: The region around Babylon maintained a large and established Jewish population, which operated under the legal and tax-collecting authority of the exilarch.12
• Manichaeism: Founded by Mani in southern Babylonia, this religion spread rapidly before facing severe persecution by the Zoroastrian clergy, who viewed it as a dangerous heresy.145
• Other Traditions: The region also hosted adherents of Mandaeanism, gnosticism, and older Babylonian pagan cults.12