Avestan

Avestan (/əˈvɛstən/ ə-VESS-tən) is the liturgical language of Zoroastrianism. It belongs to the Iranian branch of the Indo-European language family and was originally spoken during the Old Iranian period (c. 1500 – 400 BCE) by the Iranians living in the eastern portion of Greater Iran.

After Avestan became extinct, its religious texts were first transmitted orally until being collected and put into writing during the Sasanian period (c. 400 – 500 CE). The extant material falls into two groups: Old Avestan (c. 1500 – 900 BCE) and Younger Avestan (c. 900 – 400 BCE). The immediate ancestor of Old Avestan was the Proto-Iranian language, a sister language to the Proto-Indo-Aryan language, with both having developed from the earlier Proto-Indo-Iranian language. As such, Old Avestan is quite close in both grammar and lexicon to Vedic Sanskrit, the oldest preserved Indo-Aryan language.