The Forgotten War Between Christians and Zoroastrians
A 6th-century clash of faith and empire that shaped the world we live in

In the 6th century, the world was divided by two great superpowers: the Christian Byzantine Empire in the west and the Zoroastrian Sasanian Empire in the east. These were not just political rivals; they were also the defenders of two very different faiths. For Byzantines, Christianity was truth, empire, and identity. For the Sasanians, Zoroastrianism was the sacred fire that kept their kingdom together. The rivalry was unavoidable. Politics and religion were tied so tightly that an attack on one was seen as an attack on the other.
What Was Zoroastrianism?
Zoroastrianism was already a very old religion by the 6th century. Founded by the prophet Zoroaster (or Zarathustra) in ancient Iran, it preached the eternal battle between good (Ahura Mazda, the Wise Lord) and evil (Angra Mainyu, the destructive spirit). Fire temples, priests, and rituals kept this cosmic struggle alive in daily life. It was not just personal faith; it was the official state religion of the Sasanian Empire. To be Persian meant to be a Zoroastrian. That made Christians inside Persia a political problem.
Christians Under Zoroastrian Rule
Christian communities had existed in Mesopotamia and Persia for centuries, but by the 6th century, they were viewed with suspicion. They were followers of the rival empire’s religion. When Rome became Christian under Constantine and later rulers, Persian kings saw Christians in their lands as possible spies or traitors. At times, this suspicion turned violent. Churches were destroyed, clergy were executed, and Christians were pressured to worship fire or honor Persian gods. These weren’t constant persecutions, but waves of hostility often tied to wars with Byzantium.
Zoroastrians Under Christian Rule
The same was true on the other side. In Byzantine lands, Zoroastrians were rare, often merchants or captives, but they were seen as dangerous outsiders. Christian leaders denounced them as “fire-worshippers” and accused them of serving demons. Laws restricted their worship, banned their temples, and pushed them toward conversion. The 6th century saw especially harsh policies under Emperor Justinian, who sought to make Christianity the unquestioned faith of the empire. To him, non-Christians were not just wrong but a threat to social order.
Religious Justification for Violence
Neither side saw the other as just another religion. Christians believed Zoroastrians were idolaters trapped in satanic lies. Zoroastrians believed Christians were rejecting the cosmic truth of Ahura Mazda and endangering the balance of good and evil. In a world where religion and politics were inseparable, tolerance was a rare luxury. The wars between the two empires became holy struggles, framed as battles not just for land but for the soul of humanity. Both sides claimed divine support. Both sides committed violence in God’s or Mazda’s name.
The Great Wars of the 6th Century
The 6th century was full of conflict between Byzantium and Persia. Leaders like Emperor Justinian and the Persian King Khosrow I traded victories and defeats. Cities such as Antioch, Dara, and Nisibis saw constant sieges and changing rulers. Ordinary people—Christians, Zoroastrians, Jews, and others—suffered the most. Religious identity determined loyalty. In times of war, being the “wrong” religion could mean exile, execution, or forced conversion. What started as political rivalry often turned into religious persecution.
The Use of Propaganda
Both sides used propaganda to demonize the other. Christian texts described Persians as worshippers of fire and demons, while Zoroastrian writings painted Christians as agents of chaos who rejected sacred order. Preachers and priests on both sides used fear to keep their followers loyal. For ordinary believers, the enemy wasn’t just another empire—it was evil itself. This mindset made cruelty easier to justify. When soldiers burned temples or churches, they believed they were serving the divine.
What the Scholars Say
Historians point out that this rivalry was less about theology and more about power. Richard Payne, a scholar of Late Antiquity, notes that Persian rulers used Zoroastrianism to strengthen the empire’s unity, while Byzantines did the same with Christianity. Both empires understood religion as a political weapon. In reality, ordinary Zoroastrians and Christians lived side by side for centuries, trading, marrying, and sometimes even worshipping in secret together. The violent clashes were driven more by rulers than by common people. Still, once unleashed, religious hatred often spread beyond politics.
Why the 6th Century Matters
The 6th century was not the end of the Christian–Zoroastrian conflict. By the early 7th century, another religion—Islam—would rise in Arabia and sweep through both empires. Zoroastrianism would nearly vanish, surviving mainly in small communities in Iran and India (the Parsis). Christianity would split into East and West, but remain dominant in Byzantium and Europe. The hostility of the 6th century weakened both superpowers, leaving them vulnerable to the Muslim conquests. In that sense, the Christian attacks on Zoroastrianism, and the Zoroastrian attacks on Christians, paved the way for a new world order.
Before You Go
It’s easy for modern readers to take sides—some saying Christianity was under attack in Persia, others insisting Christians were the aggressors. The truth is harsher: both faiths persecuted, both justified cruelty, and both turned belief into a weapon of empire. Christianity was not the innocent victim, and Zoroastrianism was not the noble martyr. They were locked in the same trap of power and religion feeding each other.
The clash of Christians and Zoroastrians in the 6th century is not just a forgotten skirmish—it’s a warning. Religion, once fused with empire, becomes a tool of control and violence. Christianity endured, Zoroastrianism declined, but the fear, propaganda, and brutality of that age still echo today. In a world still divided by faith, this ancient conflict deserves to be remembered.
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Sources and Further Reading
Sasanian dynasty | Significance, History, & Religion - Britannica
https://www.britannica.com/topic/Sasanian-dynasty
Byzantine–Sasanian War of 602–628 - Wikipedia
https://en.wikipedia.org/wiki/Byzantine%E2%80%93Sasanian_War_of_602%E2%80%93628
The role of religion in the foreign affairs of Sasanian Iran and the Later Roman Empire (330-630 A.D.) - ResearchGate
https://www.researchgate.net/publication/363607815_The_role_of_religion_in_the_foreign_affairs_of_Sasanian_Iran_and_the_Later_Roman_Empire_330-630_AD
Justinian I - Ecclesiastical Reform, Byzantine Empire, Law | Britannica
https://www.britannica.com/biography/Justinian-I/Ecclesiastical-policy
Richard Payne | Department of History
https://history.uchicago.edu/directory/richard-payne
Muslim conquest of Persia - Wikipedia
https://en.wikipedia.org/wiki/Muslim_conquest_of_Persia
Zoroastrianism - Wikipedia
https://en.wikipedia.org/wiki/Zoroastrianism