Proto-Indo-Iranian religion

Proto-Indo-Iranian religion is not a religion anyone practised under that name; it is a scholarly reconstruction of beliefs and rites shared by the common ancestors of the Vedic Indians and the ancient Iranians, before the two branches went their separate ways. No text or inscription records it directly. Scholars infer it by comparing what is common to the Vedas, the sacred hymns of early India, and the Avesta, the sacred texts that became Zoroastrian Iran's scripture. The exercise recovers a shared sacrificial fire cult, a sacred drink that was also worshipped as a god, a body of related divine names, and a vocabulary for "god" itself that split apart in opposite directions in the two traditions. The oldest outside evidence for any of this comes not from India or Iran but from a treaty in Bronze Age Anatolia.^[1–6]

History

Bronze Age pastoralists around an open fire ritual on a grassy plain, cIllustration · AI-generated

A reconstruction, not a record c. 2200–1500 BCE (estimated)

No people identified themselves as "Indo-Iranian," and no text from this period survives. What can be said rests entirely on comparing later Vedic and Avestan material for features neither tradition's own history explains, such as shared rituals and deities, and treating those shared features as evidence of a common source.^[1]

The Mitanni treaty c. 1380 BCE

The earliest firm evidence for any Indo-Iranian deity comes not from India or Iran but from a treaty between the Hittite king and the king of Mitanni, in what is now Anatolia, which calls on the gods Mitra, Varuna, Indra and the two Nasatyas as witnesses. All four appear later in the Vedas; in the Avesta only Mitra survives as a benevolent god, while Indra and the Nasatya-equivalent are demoted to demons, showing how far the Iranian side changed from the shared inheritance.^[2]

Key moments

c. 1350 BCEIndo-Aryan gods in a Hittite treaty · Hattusa, Anatolia

Beliefs

deva / daēva · deva / daēuua

a being that shines; a god

Both branches inherited the same word for "god" (Vedic deva, Avestan daeva, related to Latin deus), and both also kept a second term, Vedic asura and Avestan ahura. Afterwards the two traditions moved in opposite directions: Iran exalted the ahuras and turned the daevas into demons, while in India the asuras increasingly came to mean demons instead.^[5]

Agni / Ātar · Agni / Ātar

fire, personified as a god

Both branches shared a sacrificial fire cult centred on fire as a deity in its own right, Agni in the Vedas and Ātar in the Avesta, through which other offerings were believed to reach the gods.^[3]

People

Mitra / Miθra · Mitra / Miθra

deity

A god of covenant and oath shared by both branches: the Vedic Mitra is already named in a 14th-century-BCE treaty, though he remains a relatively minor Vedic figure, while the Iranian Miθra grew into one of Zoroastrianism's most important divine beings.^[6]

Art & objects

Public-domain objects from museum collections. Select one to see it at the museum.

Bactrian camelBactria-Margiana Archaeological Complex, Bronze Age, ca. late 3rd–early 2nd millennium BCE

Compartmented stamp sealBactria-Margiana Archaeological Complex, Bronze Age, ca. late 3rd–early 2nd millennium BCE

Stamp sealBactria-Margiana Archaeological Complex, Bronze Age, ca. late 3rd–early 2nd millennium BCE

Openwork stamp seal: figure holding snakesBactria-Margiana Archaeological Complex, Bronze Age, ca. late 3rd–early 2nd millennium BCE

Seated femaleBactria-Margiana Archaeological Complex, Bronze Age, ca. late 3rd–early 2nd millennium BCE

Shaft-hole axe head with bird-headed demon, boar, and dragonBactria-Margiana Archaeological Complex, Bronze Age, ca. late 3rd–early 2nd millennium BCE

How we know

How the religion is reconstructed

Because no Indo-Iranian text survives, everything here depends on comparing two later, independently preserved literatures: the Vedas of ancient India and the Avesta of ancient Iran. Shared ritual terms, shared deity names, and shared turns of phrase are taken as evidence of a common source rather than as later borrowing between the two.^[1]

Glossary

haoma / soma · haoma / soma: A sacred drink prepared from a plant (botanically disputed) and ritually pressed in both Iran and India; also worshipped in its own right as a divine being in the Avesta and the Vedas alike.^[4]
deva / daēva · deva / daēuua: A shared Indo-Iranian word for "god," related to Latin deus; in Zoroastrian Iran it came to mean "demon," while in Vedic India it stayed the ordinary word for a (good) god.^[5]

Sources

Each statement above was checked against published sources; the verdict says whether it stood as written, was corrected or was hedged.

Last fact-checked 6 October 2026.