Avestan period

The Avestan period (c. 1500 – c. 400 BCE) is the period of Iranian history when the collection of canonical texts of Zoroastrianism called the Avesta were produced. The period saw important developments to religious thought and to Iranian mythology, historiography and literature exemplified by the Shahnameh.

Scholars can reliably distinguish between two different linguistic strata in the Avesta labeled "Old Avestan" and "Young Avestan". These two strata represent two different stages in the development of the Avestan language and the society of its speakers. The Old Avestan society is the one to which Zarathustra and his immediate followers belonged. The Young Avestan society is less clearly delineated and reflects a longer time span.

There is a varying level of scholarly consensus on the chronology and geographical extent of the Avestan period. Scholarship largely agrees that it reflects the eastern portion of Greater Iran. Early scholarship placed Zarathustra in the 6th century BCE. More recent scholarship, however, places him several centuries earlier, and this dating has become widely accepted. This early chronology would place the Avestan period c. 1500 – c. 400 BCE, mostly predating the Achaemenid Empire of 550 – 330 BCE. The early chronology would thus make the Avestan period the oldest period of Iranian history for which literary sources are available.