Written by A standalone piece
A religion with barely a hundred thousand adherents today once cast a shadow across half the known world — revered in the Greek imagination as the fountainhead of Eastern wisdom, carried along the trade routes of Asia as far as the Chinese capitals, and enthroned as the faith of the great Persian empires. The reach of Zoroastrianism is one of the most under-told stories in religious history. This piece traces that footprint across three domains — the Greek mind, the Silk Road, and the Persian throne — and states each as precisely as the evidence allows, because the accurate version is impressive enough without a single embellishment.
In the Greek imagination
To the Greeks, Zoroaster was a figure of almost mythic authority — the archetype of the wise man of the East, the master of a knowledge older and deeper than their own. The references run across centuries and across the major names of Greek intellectual life.
Herodotus, in the fifth century BCE, described the Magi — the Persian priestly class — and their rites, their role in sacrifice and dream interpretation, fixing them in the Greek understanding of Persia.[^1] Plato, or the tradition close to him, names “Zoroaster son of Oromazes” as the source of the magēia taught to the Persian princes.[^2] And a whole line of authorities placed him in staggering antiquity: Eudoxus of Cnidus and Aristotle were cited for the figure of 6,000 years before Plato; Hermippus of Smyrna claimed to have studied the Zoroastrian writings; Plutarch gave 5,000 years before the Trojan War and described the opposition of Oromazes (Ahura Mazda) and Areimanios (Ahriman); and Diogenes Laertius and Pliny the Elder gathered and transmitted these traditions.[^3] The Greek word for ritual expertise, magēia — the root of the English magic — derives directly from the magoi, the Persian priests: a linguistic fossil of how completely the Greeks identified hidden knowledge with the Iranian tradition.[^4]
One famous strand should be stated carefully, because it is a tradition rather than a documented fact: the later biographers of Pythagoras — Porphyry and Iamblichus among them — report that he traveled east and learned from the Magi, sometimes from a teacher called “Zaratas.”[^5] This belongs to a recognizable Greek pattern of crediting the great philosophers with Eastern apprenticeships, and it cannot be taken as established history. But it is genuine and useful evidence of something real: that the Greeks themselves regarded Persian Magian wisdom as a source worth claiming, a wellspring their own sages were said to have drunk from. The legend testifies to the prestige, even where it fails as biography.
Along the Silk Road
If the Greeks carried Zoroaster in their imagination, the Sogdians carried his religion across a continent. The Sogdians were an Iranian people of Sogdiana — the region of modern Uzbekistan and Tajikistan, around Samarkand and Bukhara — and for most of the first millennium CE they were the supreme merchants of the Silk Road, the middlemen of Eurasian trade.[^6] Their home religion was predominantly Zoroastrianism, and they carried it with them along the routes, though Sogdian communities were religiously plural and their Mazdaism varied in local ways from the Iranian “orthodox” form.[^7]
The eastward reach is striking. Zoroastrian Sogdians established a visible presence in China: the “Sogdian Ancient Letters” found near Dunhuang, dated around 313 CE, are among the earliest firm evidence, and the Chinese coined a dedicated character, 祆 (xiān), specifically to designate this foreign faith.[^8] Fire temples were erected for the Sogdian communities in the Chinese capitals; their communities were administered under officials titled sabao; and the tombs of Sogdians buried in China — such as those excavated at Xi’an — depict Zoroastrian fire ceremonies, complete with priests wearing the ritual mouth-cover (padam) to avoid polluting the sacred flame with their breath.[^9] So thoroughly was the faith woven into the trade world that a Pahlavi text preserved the legend that the Avesta itself had once been kept in the citadel of Samarkand, the Sogdian capital.[^10]
One distinction keeps this precise: the Achaemenid Royal Road — Darius’s great highway from Sardis to Susa, with its famous courier relay described by Herodotus — is not the same thing as the later Silk Road network on which the Sogdians flourished. Both connected the Persian world outward; they belong to different eras. It was the Silk Road, in the first millennium CE, that carried Zoroastrian fire temples to the gates of Tang China.[^11]
The faith of empires
The grandest part of the footprint is the imperial one, and here precision matters most, because the careless version (“the state religion since Zarathustra”) collapses under scrutiny while the accurate version stands firm.
Zarathustra himself long predates any Persian state — he was an eastern Iranian prophet of the deep second millennium BCE, and his faith spread among the Iranian peoples across many centuries before any empire adopted it.[^12] The first empire to place his God at its center was the Achaemenid (550–330 BCE): from Darius I onward, the kings proclaimed Ahura Mazda in their inscriptions — “by the favor of Ahura Mazda I am king” — making Mazda-worship the religion of the Persian monarchy, even as scholars debate how fully the early Achaemenids followed Zarathustra’s specific reform.[^13] That royal status was interrupted by Alexander’s conquest and the Greek Seleucid rule that followed, and only loosely held under the Parthians.[^14]
It was under the Sasanian Empire (224–651 CE) that Zoroastrianism became a formal, organized state religion in the fullest sense: an established church with a structured priesthood (the mowbeds), tied closely to the throne. The third-century high priest Kartir left his own inscriptions boasting of the faith’s promotion and the suppression of rivals, and it was in this era that the long-oral Avesta was at last gathered and committed to writing.[^15] This Sasanian Zoroastrian state endured for over four centuries — until the Arab-Islamic conquest of Persia in the seventh century CE ended it, after which the faith dwindled to the minority it remains.[^16]
So the true imperial story is this: Ahura Mazda at the heart of the Persian monarchy from the Achaemenids, and the organized state religion of the mighty Sasanian Empire for four centuries — a thousand-year arc of royal and imperial standing, though not the unbroken “state religion since Zarathustra” of looser tellings. The accurate version is already vast.
The forgotten reach
Set the three domains together and the footprint is undeniable: a prophet the Greeks ranked among the most ancient and authoritative sages in the world; a faith carried by Sogdian merchants across the whole breadth of Asia to the temples of Tang China; and the religion of the Persian throne from Darius to the fall of the Sasanians, a span of a thousand years. For a tradition now reduced to a small and scattered community, that is an extraordinary reach — and the fact that so little of it is remembered today is itself part of the story this series keeps returning to. The footprint was real, it was vast, and the evidence for it — Greek, Chinese, Persian, archaeological — is there to be read. The facts, stated accurately, are more than enough.
Notes
[^1]: On Herodotus’s account of the Magi and Persian religious practice, see Herodotus, Histories 1.101 and 1.131–132.
[^2]: On the naming of “Zoroaster son of Oromazes” as the source of Persian magēia, see Plato (or the Platonic tradition), Alcibiades I 122a.
[^3]: On the classical long chronology and the cluster of authorities: Diogenes Laertius, Lives of the Eminent Philosophers I.2 (citing Eudoxus and Aristotle, 6,000 years before Plato); Pliny the Elder, Natural History 30.2–3 (citing Eudoxus and Hermippus of Smyrna); and Plutarch, Isis and Osiris 46–47 (369d–e), on Oromazes vs. Areimanios and the 5,000-years-before-Troy figure.
[^4]: On magēia / “magic” deriving from the magoi, the Persian priestly class, see standard etymological treatments and the discussion in the companion piece “Borrowed Names.”
[^5]: On the tradition that Pythagoras studied with the Magi (or “Zaratas”), see Porphyry, Life of Pythagoras, and Iamblichus, On the Pythagorean Life; modern scholarship treats this as a legendary topos of Eastern apprenticeship rather than documented biography.
[^6]: On the Sogdians as the dominant Silk Road merchants of the first millennium CE, based around Samarkand and Bukhara, see the Smithsonian “Sogdians” project (sogdians.si.edu) and standard treatments of Silk Road trade.
[^7]: On predominant Sogdian Zoroastrianism with local variation and religious pluralism (e.g., mourning practices at variance with Iranian orthodoxy, veneration of multiple deities), see the Smithsonian “Sogdians” project, “Believers, Proselytizers, Translators,” and Nicholas Sims-Williams’s work on Sogdian religion.
[^8]: On the “Sogdian Ancient Letters” (c. 313 CE, near Dunhuang) as early evidence and the Chinese character 祆 (xiān) coined for the religion, see the standard scholarship on Zoroastrianism in China.
[^9]: On fire temples in the Chinese capitals, the sabao officials administering Sogdian communities, and tomb iconography (Xi’an) showing fire ceremonies and priests in the padam mouth-cover, see Moritz Huber, Ancient Zoroastrianism in China (Asiatische Forschungen 160), and related archaeological studies.
[^10]: On the Pahlavi legend (Shahristāniha ī Ērān) that the Avesta was preserved in the citadel of Samarkand, see Nicholas Sims-Williams’s discussion and the avesta.org survey “Ancient Sogdiana.”
[^11]: On the Achaemenid Royal Road (Sardis to Susa) and its courier relay, distinct from the later Silk Road network, see Herodotus, Histories 5.52–54.
[^12]: On Zarathustra’s eastern Iranian / Central Asian origin in the deep second millennium BCE, predating the Persian state, see Mary Boyce, A History of Zoroastrianism, vol. 1 (Leiden: Brill, 1975).
[^13]: On Achaemenid royal proclamation of Ahura Mazda from Darius I (e.g., the Behistun Inscription) and the scholarly debate over the early Achaemenids’ relationship to Zarathustra’s reform, see Pierre Briant, From Cyrus to Alexander: A History of the Persian Empire (Winona Lake: Eisenbrauns, 2002), and Boyce, A History of Zoroastrianism, vol. 2.
[^14]: On the interruption of Zoroastrian royal status under Alexander and the Seleucids, and its looser standing under the Parthians, see Boyce, Zoroastrians: Their Religious Beliefs and Practices (London: Routledge, 1979).
[^15]: On the Sasanian establishment of Zoroastrianism as an organized state religion, the priesthood (mowbeds), the high priest Kartir and his inscriptions, and the written codification of the Avesta, see Boyce, Zoroastrians, and the Sasanian Avesta scholarship.
[^16]: On the end of the Zoroastrian state with the Arab-Islamic conquest of Persia (7th century CE) and the subsequent reduction of the faith to a minority, see Boyce, Zoroastrians, and Richard Frye, The Heritage of Persia (London: Weidenfeld & Nicolson, 1962).