The Avestan period (1500-500 BCE) is the period in the history of the Iranian peoples when the Avesta was produced. It saw important contributions to both the religious sphere, as well as to Iranian mythology and its epic tradition.
Scholars can reliably distinguish between two different linguistic strata in the Avesta; Old Avestan and Young Avestan, which are interpreted as belonging to two different stages in the development of the Avestan language and society. The Old Avestan society is the one to which Zarathustra himself and his immediate followers belonged to. The Young Avestan society is less clearly delineated and reflects a larger time span.
There is a varying level of agreement on the chronological and geographical boundaries of the Avestan period. Regarding the geographical extent of the Avesta, modern scholarship agrees that it reflects the eastern portion of Greater Iran. Regarding the chronological extent, scholarship initially focused on a short chronology, that places Zarathustra in the 6th century BCE. More recently a long chronology, that places him several centuries earlier, has become widely accepted. This long chronology would largely place the Avestan period before the Achaemenid period, making it the earliest period of Iranian history for which literary sources are available.
Avesta and
The primary source for the Avestan period are the texts of the Avesta, i.e., the collection of canonical texts of Zoroastrianism. All material in the Avesta is composed in Avestan, an otherwise unattested Old Iranian language. Scholars do distinguish between at least two stages of Avestan; namely Old Avestan and Young Avestan.
Gatha (Zoroaster)Yasna Haptanghaiti and
The Old Avestan material consists of the Gathas composed by Zarathustra himself, the Yasna Haptanghaiti, and a number of mantras, namely the Ashem Vohu, the Ahuna Vairya and the Airyaman ishya. These Old Avestan texts are assumed to have been composed close together and must have crystallized early on, possibly due to the associating with Zarathustra himself.