Origins of Religions · Episode 04 · c. 1200 BC – today
Zoroastrianism
How Zoroastrianism began among Iranian herders, what Zarathustra taught in the Gathas about Ahura Mazda, truth and the lie, judgement and renewal, its place under the Achaemenid and Sasanian kings, the debated influence of its ideas on Judaism, Christianity and Islam, its survival after the Arab conquest in Yazd and Kerman, the Parsis of India, and Zoroastrians and Nowruz today. Episode 04 of the Origins of Religions series.
Interactive 3D film6 minc. 1200 BC to todayPublished 2026-10-13
In the city of Yazd in Iran, a sacred fire has been kept burning, by tradition, for over 1,500 years. Zoroastrians pray facing a source of light, as a symbol of their god’s wisdom and purity.
Today there are only around 100,000 to 200,000 Zoroastrians, mostly in India, where they are called Parsis, and in Iran. Yet for more than a thousand years this was the faith of great empires.
Prologue · Episode 04 of the Origins of Religions series
A small faith with a long reach
Zoroastrians today
~110,000–200,000
estimates vary
Largest communities
India, Iran, North America
Zoroastrians do not worship fire; fire is a symbol and a focus of prayer.
Zarathustra, called Zoroaster by the Greeks, lived among Iranian-speaking herders somewhere in Central Asia or eastern Iran. His language, Avestan, is a close cousin of the Sanskrit of the Rigveda.
His people shared gods and rituals with the Vedic Indians. But in Iran, the word daeva came to mean demon, while in India deva means god.
His hymns describe a violent world of cattle raids and warrior bands. Scholars date him anywhere from about 1500 to 500 BC; many favour around 1200 to 1000 BC, from the archaic language of his hymns.
Chapter I · Step 1
A world of cattle raiders
Avestan Sister language of Vedic Sanskrit
ahura / asura “lord”: good in Iran, demonic in later India
daeva / deva demon in Iran, god in India
Zoroastrian tradition places the prophet much earlier or later in different sources; there is no scholarly consensus.
Zarathustra’s own words survive in seventeen hymns, the Gathas. He taught that there is one supreme, wise and good god, Ahura Mazda.
The world is the scene of a struggle between asha, truth and right order, and druj, the lie. Every person must freely choose a side, with good thoughts, good words and good deeds.
After death, each soul crosses the Chinvat bridge, which becomes broad for the righteous and narrow as a blade for the wicked.
At the end of time a saviour will come, the dead will rise, and the world will be made perfect again. These were remarkably new ideas.
Chapter I · Step 2
The wise lord and the choice
Ahura Mazda The wise lord
Asha / Druj Truth and order / the lie
Humata, hukhta, hvarshta Good thoughts, good words, good deeds
The Achaemenid kings of Persia built the largest empire the world had yet seen. In his great inscription at Behistun, around 520 BC, Darius I says he rules “by the favour of Ahuramazda”.
Whether the early Persian kings followed Zarathustra’s teaching in full is debated, but they honoured the same god.
They also tolerated other religions. Cyrus allowed the Jews exiled in Babylon to return to Jerusalem and rebuild their temple, in 538 BC. The Bible calls him God’s anointed.
Under Persian rule, Jewish writings began to speak more of angels and a chief adversary, Satan, of the resurrection of the dead, and of a final judgement.
Many scholars think contact with Zoroastrian ideas contributed to this. Others stress developments within Judaism itself. The question is still debated.
Through Judaism, these ideas passed into Christianity and Islam. In the Gospel of Matthew, the wise men from the east who visit the infant Jesus are magi, the Persian word for Zoroastrian priests.
Chapter II · Step 4
Ideas that travelled
Heaven and hell Judgement of each soul
Resurrection The dead rise at the end of time
Saviour A world-renewing figure to come
Magi Persian priests, in the Gospel of Matthew
Zoroastrianism has sometimes been called the first monotheism; scholars debate whether its dualism of good and evil fits that label.
When the Sasanian dynasty took power in Iran in 224, Zoroastrianism became a state religion with a powerful priesthood. The high priest Kartir had inscriptions carved boasting of his campaigns against other faiths.
Great fire temples were founded, like Adur Gushnasp at Takht-e Soleyman. The Avesta, long passed on by memory, was finally written down in a special alphabet, probably in the 5th or 6th century.
Rivals appeared: the prophet Mani, born in 216, founded Manichaeism, a religion of light and darkness that spread from Rome to China before dying out.
A group of Zoroastrians sailed to Gujarat in India, according to the Qissa-i Sanjan, a later poem; dates between the 8th and 10th centuries are proposed. They became known as Parsis, “Persians”.
Legend says a local king showed them a full bowl of milk: there was no room. Their priest added sugar, to show they would sweeten the land without overflowing it.
Under British rule, Parsis in Bombay became leading merchants, industrialists and reformers, out of all proportion to their small numbers.
Chapter III · Step 7
The Parsis of India
8th–10th c. Arrival at Sanjan (date debated)
Udvada Home of the Iranshah fire, India’s oldest
19th c. Bombay’s Parsi merchants and industrialists
Zoroastrian numbers are falling, because of low birth rates, emigration and strict rules on marrying outside the faith. Communities debate whether to accept converts.
Yet one Zoroastrian festival is celebrated by around 300 million people: Nowruz, the Iranian New Year at the spring equinox, now a UNESCO-listed heritage across Iran, Central Asia and beyond.
The winged symbol, the faravahar, has become an emblem of Iranian identity, for people of many faiths.
Zarathustra asked each person to choose between truth and the lie. That idea of a moral choice with eternal consequences is one of the most influential in the history of religion.
Next: Judaism, a faith born among a small people between great empires, whose scriptures would shape Christianity and Islam.
Epilogue
The choice
?1200 BC Zarathustra and the Gathas
550–330 BC Achaemenid kings
224–651 Sasanian state religion
8th–10th c. Parsis in India
The series
00The Origins of Religions (overview)
01The First Beliefs
02The Ancient Gods
03Hinduism
04 Zoroastrianism (this film)
05Judaism
06Buddhism and Jainism
07Confucianism and Daoism
08Shinto
09Christianity
10 Islam (coming soon)
11 Sikhism (coming soon)
12 Spirits, Brahmins and the Buddha: Southeast Asia (coming soon)
The still images on the chapter cards are AI-generated illustrations. Outlines are approximate.