Avesta

The Avesta serves as the central religious text for Zoroastrianism, a collection of hymns and laws composed in the ancient Avestan language. While tradition attributes the core teachings to the prophet Zoroaster, the text itself emerged from centuries of oral transmission before being codified during the Sasanian era between 224 and 651 CE. The original Sasanian version disappeared after the Islamic conquest of Iran, meaning today's versions consist of fragments and later recensions rather than a single unified volume.

Scholars view this corpus as the largest body of literature from the Old Iranian period and the oldest texts written in any Iranian tongue. The earliest surviving manuscript dates to 1323 CE, preserving insights into a linguistic and cultural history that would otherwise be lost. Modern critical editions rely heavily on these medieval copies alongside earlier fragmented sources to reconstruct the sacred canon. [edit]