Religious policy and the range of religious belief across the empire, including the worship of Ahura Mazda, Bel Marduk in Babylon and Yahweh in Judah; the Zoroaster/Zarathustra debate and Xerxes's daiva inscription (XPh); rituals and practice, including the role of the Magi and fire ritual; royal funerary customs and the rock-cut tombs at Naqsh-e Rustam; and the tolerance of local cults, including the Cyrus Cylinder and the restoration of the Jerusalem Temple

What this dot point is asking

NESA expects you to explain Persia's religious POLICY and the actual range of religious belief across an empire that stretched from Egypt to India, covering the worship of Ahura Mazda, Bel Marduk in Babylon and Yahweh in Judah, the unresolved scholarly debate over Zoroaster/Zarathustra and Xerxes's daiva inscription, ritual practice including the Magi and fire ritual, royal funerary custom at the rock tombs of Naqsh-e Rustam, and the interpretive debate over "the extent of religious tolerance," using the Cyrus Cylinder and the restoration of the Jerusalem Temple as the central test case. Strong answers cite royal inscriptions (Behistun, DNa, XPh) and ancient written sources (Herodotus, Ezra) alongside archaeological evidence, and weigh named historians against each other rather than treating "Persian tolerance" as a settled fact.

The answer

The range of belief across the empire: Ahura Mazda, Marduk, and Yahweh

The Achaemenid empire was religiously diverse by necessity. At its Persian core, the kings invoked Ahura Mazda as the sole source of royal legitimacy. In Babylon, the ancient cult of Bel Marduk continued largely undisturbed, its priesthood and temple estates intact. In Judah, the god Yahweh's temple in Jerusalem was rebuilt with royal permission and, eventually, royal confirmation. Further west, Xerxes himself sacrificed 1,000 oxen to the Greek goddess Athena Ilias when he visited Troy, and Magi poured libations to the Trojan heroes (Herodotus 7.43), showing that royal religious respect could extend even to a foreign pantheon with no administrative stake in the empire at all.

This range was not accidental tolerance but administered pluralism. Wouter Henkelman's study of the Persepolis Fortification Archive, tens of thousands of Elamite administrative tablets recording rations issued across the Persian heartland, shows the state provisioning religious offerings ("lan") to Ahura Mazda and to a wider set of Iranian and Elamite deities side by side, evidence that even at the imperial core religious practice was plural, not narrowly monotheistic.

Ahura Mazda and royal ideology

Ahura Mazda ("Wise Lord") is the only god named in Darius's and Xerxes's own royal inscriptions. The Behistun Inscription, carved on a cliff at Bisitun after Darius suppressed a wave of revolts following his seizure of the throne in 522-521 BC, credits Ahura Mazda alone with every victory and frames the defeated pretenders as followers of "the Lie" (drauga) overthrown because Darius himself followed "the Truth" (arta). The tomb inscription DNa at Naqsh-e Rustam opens with a formula reused across several royal inscriptions: "A great god is Ahuramazda, who created this earth, who created yonder sky, who created man, who created happiness for man," before naming Darius as the king Ahura Mazda made. Kingship and cosmic creation are fused in a single sentence.

This exclusive royal rhetoric is notable because Darius and Xerxes name only Ahura Mazda; other Iranian deities later named in Achaemenid inscriptions, such as Mithra and Anahita, appear only from the reign of Artaxerxes II onward, generations after Xerxes. Within the Darius-Xerxes period specifically, royal inscriptions present a striking, deliberate focus on one god as the guarantor of the throne.

The Zoroaster/Zarathustra debate

Whether Darius and Xerxes practised the religion founded by the prophet Zoroaster (Zarathustra) is a genuine, unresolved scholarly debate, and it turns on dating. The Greek chronographer Xanthus of Lydia, preserved by the later writer Diogenes Laertius, placed Zoroaster "6,000 years" before Xerxes's crossing into Greece (480 BC), a legendary, symbolic figure rather than a historical date; other classical writers gave equally fantastical, wildly different figures. Modern scholars instead date Zoroaster on linguistic grounds: the Gathas, hymns attributed to Zoroaster within the later Avesta, are composed in an archaic form of Avestan close to the language of the Rig Veda, which most specialists take to place their composition somewhere in the later second millennium BC, centuries before the Achaemenid dynasty was founded by Cyrus around 550 BC. The exact date remains contested and imprecise.

This dating gap fuels the debate. Mary Boyce argued that the Achaemenid kings, especially from Darius onward, were substantially Zoroastrian, reading the exclusive Ahura Mazda/Truth-versus-Lie ideology of the royal inscriptions as evidence of real doctrinal conviction. Pierre Briant is far more cautious: he stresses that Zoroaster's name never appears in a single Achaemenid royal inscription, and treats royal devotion to Ahura Mazda as a royal ideology legitimising kingship, not confirmed proof that Darius and Xerxes were practising Zoroastrians in the sense the later, codified Avesta describes. The safest exam position states the debate rather than asserting either side as settled fact.

Xerxes's daiva inscription (XPh)

The inscription known to scholars as XPh, found at Persepolis, is Xerxes's own account of suppressing a form of worship. In it, Xerxes states that among the countries he ruled there was one where the daivas, a class of divine beings that Zoroastrian tradition rejects as false gods or demons, were worshipped. He records that he destroyed that sanctuary of the daivas, proclaimed "the daiva shall not be worshipped," and instituted the worship of Ahura Mazda there instead. The word itself is revealing: "daiva" is the Iranian cognate of the Vedic Sanskrit "deva" (a god), so the same ancient word split into "demon" in one branch of Indo-Iranian religion and "god" in the other, a linguistic fossil of a real theological realignment.

Xerxes never names the country or the specific sanctuary, and this silence is the crux of the debate. Older scholarship sometimes linked the passage to Babylon, connecting it to Xerxes's suppression of Babylonian revolts in 484-482 BC and a later Greek and Babylonian priestly tradition that he damaged the cult of Marduk. Historians including Amelie Kuhrt and Caroline Waerzeggers, working from the Babylonian temple archives themselves, caution against this identification: the archival record does not confirm a single dramatic act of religious destruction in Babylon, and Waerzeggers's study of the "end of archives" after 484 BC points instead to a punitive administrative reprisal against specific rebel-linked elites, not necessarily a religious campaign against Marduk's cult as such. The daiva inscription's target may equally have been elsewhere in the empire. What is certain is that the daiva inscription complicates any simple claim of universal Achaemenid tolerance, since Xerxes plainly claims to have suppressed some cult, somewhere, in language that echoes Behistun's Truth-versus-Lie framing.

Rituals and practice: the Magi and fire ritual

The Magi were, per Herodotus (1.101), originally one of the six tribes of the Medes; under the Achaemenids they became Persia's hereditary priestly caste, present at sacrifice, royal ritual, and the interpretation of omens. Herodotus (1.132) describes Persian sacrifice as lacking the Greek apparatus of temples, altars, and cult statues: offerings were typically made on mountain tops, with a Magus required to be present to chant a theogony over the victim before the meat was carried away uneaten by the sacrificer. Fire itself, alongside earth, water, and the sky, was treated as a sacred element requiring careful ritual handling rather than casual use, and fire altars appear repeatedly in Achaemenid royal art, most strikingly in the reliefs carved before the king at each of the rock-cut tombs of Naqsh-e Rustam.

The Magi's ritual role extended to divination and, at times, disturbing acts of ritual violence. Before Xerxes's crossing into Greece, Herodotus (7.37) records the Magi interpreting a solar eclipse as favourable to Persia. At the Nine Ways (Ennea Hodoi) in Thrace, Herodotus (7.113-114) describes Xerxes's forces sacrificing white horses to the river Strymon, and, in a rite Herodotus attributes to the Magi, burying nine local boys and nine girls alive, a grim reminder that "religious tolerance" and "ritual practice" in this period should not be softened into a modern, comfortable image. On the more conciliatory end of the same spectrum, at Troy Xerxes sacrificed 1,000 oxen to Athena Ilias and had the Magi pour libations to the Homeric heroes (Herodotus 7.43), showing that royal religious performance could flex from severe suppression to warm accommodation depending entirely on political circumstance.

Royal funerary customs and the rock tombs at Naqsh-e Rustam

Achaemenid royal funerary practice sits in real tension with later Zoroastrian purity law, and this tension is itself examinable. Herodotus (1.140) records that, distinctively among Persians, the Magi exposed a corpse for a bird or dog to tear before burial, close in spirit to the exposure rite (later formalised as the dakhma, or "tower of silence") that developed Zoroastrianism prescribes to avoid polluting the sacred earth or fire with a corpse. Yet the kings themselves were not exposed: Herodotus records that Persian nobility instead embalmed the body in wax before burial, and the Achaemenid kings from Darius onward were entombed in monumental rock-cut chambers, direct burial in stone rather than exposure.

Four royal tombs are cut roughly 20 metres up a cliff face at Naqsh-e Rustam, near Persepolis, traditionally assigned to Darius I, Xerxes I, Artaxerxes I, and Darius II. Only Darius's tomb is securely identified, by its own trilingual inscription (DNa, with a separate inscription, DNe, naming the throne-bearing figures below); the other three are assigned by scholarly consensus based on their position and relative artistic style, not by their own inscriptions, a source-critical caution worth stating explicitly in an exam answer. Each tomb facade is cut in a cruciform shape: the king stands on a raised dais supported by rows of throne-bearers representing subject peoples of the empire, faces a tall fire altar, and is shown beneath a winged disk symbol, popularly associated with Ahura Mazda in modern usage but never explicitly identified as the god in any accompanying inscription, so this specific identification should be flagged as probable rather than certain.

The tolerance of local cults: the Cyrus Cylinder and the Jerusalem Temple

The central evidence for Achaemenid religious tolerance predates Darius and Xerxes but sets the template they inherited and, in the case of Jerusalem, personally continued. After Cyrus took Babylon in 539 BC, the Cyrus Cylinder, a clay cylinder inscribed in Akkadian in the conventional genre of a Mesopotamian royal building and restoration inscription, records him restoring the cult statues of Marduk and other Babylonian gods to their shrines, reversing what the text presents as the impious policies of his predecessor Nabonidus, and framing Marduk himself as having chosen Cyrus as king. Historians such as Amelie Kuhrt argue firmly against the popular modern framing of the Cylinder as a proto "charter of human rights": it follows an established genre of self-legitimising royal rhetoric used by Assyrian and Babylonian kings for centuries before Cyrus, so its claims of piety are conventional, not disinterested.

The Jerusalem case shows the pattern was not merely rhetorical, and it runs directly through Darius's own reign. Ezra 1 records Cyrus issuing a decree permitting the Jewish exiles to return to Jerusalem and rebuild the Temple of Yahweh, with the sacred temple vessels restored to them. Work stalled amid local opposition, and Ezra 6 records Darius I searching the royal archives, confirming Cyrus's original decree, and ordering the project funded from royal revenue; the Second Temple was completed in Darius's sixth regnal year, traditionally dated to 516 BC. Continued Persian engagement with Yahweh worship is also attested later, under Darius II, in the Aramaic archive of a Jewish military garrison at Elephantine in Egypt, whose "Passover Letter" and requests for satrapal help rebuilding a destroyed local temple show both the reach and the real limits of Achaemenid religious tolerance on the ground.

Persian religion at a glance

How to read a source on this topic

Section II sources on Persian religion typically draw on royal inscriptions (Behistun, DNa, XPh), Herodotus, the biblical book of Ezra, or archaeological/administrative evidence such as the Cyrus Cylinder, the Persepolis Fortification Archive, or Egyptian temple and burial inscriptions. Four reading habits matter.

First, separate genres. A royal inscription (Behistun, DNa) is self-legitimising ideology, written to justify the king's rule to posterity; Herodotus is an outsider's ethnography, filtered through Greek categories and sometimes hostile local informants; Ezra is a religious text with its own theological agenda, presenting a foreign king's decree as evidence of Yahweh's providence; an administrative document like the Persepolis Fortification tablets is a comparatively neutral but incomplete bureaucratic snapshot. Each genre distorts in a different direction.

Second, watch for the anachronism trap. The fully codified Zoroastrian scripture, the Avesta, was compiled and canonised centuries after Xerxes, under the later Sasanian Empire. Do not assume the developed doctrinal Zoroastrianism of that later period was already the Achaemenid court religion in Darius and Xerxes's day; the "Zoroaster debate" exists precisely because this cannot simply be assumed.

Third, corroborate written sources against archaeology wherever possible. Herodotus's hostile story of Cambyses stabbing the Apis bull (3.27-29) is directly complicated by a Serapeum burial stela recording a full traditional Apis burial in his reign, a textbook case of why a written source's claims should never be accepted without checking for material evidence.

Fourth, weigh silence carefully. Xerxes's daiva inscription never names its target, and Achaemenid royal inscriptions never name Zoroaster. Historians disagree sharply about what these silences mean, so an exam answer that notices the silence and states the debate scores higher than one that fills the gap with a confident guess.

Historians on Persian religious policy

The central disagreement is between historians who read Achaemenid religious rhetoric as sincere doctrine and those who read it as pragmatic imperial ideology. Mary Boyce (Zoroastrians: Their Religious Beliefs and Practices) argued the Achaemenids, especially from Darius, were substantially Zoroastrian in genuine conviction. Pierre Briant (From Cyrus to Alexander: A History of the Persian Empire) is more sceptical, stressing that Zoroaster's name never appears in a royal inscription and treating the exclusive Ahura Mazda ideology as royal legitimation rather than confirmed doctrine. Amelie Kuhrt (The Persian Empire: A Corpus of Sources) argues the Cyrus Cylinder should be read within its Mesopotamian genre, not as a human-rights charter, and treats Achaemenid religious policy overall as pragmatic rather than principled tolerance. Caroline Waerzeggers, working from Babylonian temple archives, cautions against the older assumption that Xerxes's suppression of Babylonian revolts (484-482 BC) simply confirms a deliberate campaign against the cult of Marduk. Wouter Henkelman (The Other Gods Who Are), working from the Persepolis Fortification Archive, documents genuine administrative pluralism, state-funded offerings to a range of Iranian and Elamite deities alongside Ahura Mazda, complicating any picture of a narrowly monotheistic royal court.