The Avesta is the primary collection of sacred texts of Zoroastrianism, composed in Avestan — an Old Iranian language related to Sanskrit — across a period likely spanning many centuries. Its oldest and most sacred portion, the Gathas, consists of seventeen hymns embedded within the larger Yasna liturgy, composed in an archaic form of the language and traditionally attributed directly to the prophet Zoroaster (Zarathustra) himself, making them, if the attribution holds, among the very few surviving texts anywhere in the world plausibly written by the founder of a major world religion in their own words.
Zoroaster's actual dates remain genuinely disputed among scholars, with proposals ranging from as early as 1500 BCE to as late as the 6th century BCE — a spread of nearly a thousand years reflecting how little external corroborating evidence survives to anchor his life to a specific period. What is generally agreed is that he taught in an eastern Iranian-speaking region, proclaiming a distinctive vision of one supreme god, Ahura Mazda, locked in cosmic struggle against a destructive spirit, and calling on believers to align themselves through "good thoughts, good words, good deeds."
For centuries the Avesta was preserved entirely through oral transmission by a specialised priestly class, memorised and recited with extraordinary precision long before it was ever committed to writing. It was only under the Sassanian Empire (3rd–7th century CE) that the texts were finally written down, using a newly developed Avestan alphabet specifically engineered to capture the language's precise phonetic nuances — itself a sign of how seriously exact oral preservation was taken.
The Arab conquest of Persia in 651 CE ended Zoroastrianism's status as a state religion and began a long decline that scattered its adherents and further eroded the surviving textual tradition. What remains today represents the hard-won survival of a scripture that has spent most of its history under active threat of extinction.