protoIndoIranian

Proto-Indo-Iranian is the reconstructed common ancestor of the Indo-Iranian branch of the Indo-European language family. It is a hypothetical language identified through systematic similarities in phonology, morphology, and lexicon across its descendant languages, most notably the Indo-Aryan languages (such as Sanskrit, Hindi, Bengali, Marathi, Punjabi, Gujarati) and the Iranian languages (including Avestan, Old Persian, Persian, Kurdish, Pashto, Balochi).

Dating and geography: Most scholars place Proto-Indo-Iranian in the range of roughly 1800 to 1500 BCE. Its speakers are thought to have lived somewhere in the eastern Eurasian steppe and Central Asia, from which populations later expanded into the Iranian plateau and the Indian subcontinent.

Phonology and grammar: The reconstruction preserves a consonant system typical of Proto-Indo-European, including stops, aspirates, sibilants, nasals, and liquids, as well as a complex system of noun and verb inflections. Laryngeal elements posited for PIE may be reflected indirectly in later vowels. The language likely exhibited shared Indo-Iranian innovations after the split into the Iranian and Indo-Aryan subgroups.

Descendants and evidence: The oldest attestations come from Avestan in the Zoroastrian scriptures and Old Persian, with later Indo-Aryan evidence from Vedic Sanskrit and early Prakrits. The split produced two major subgroups, giving rise to the broad Indo-Aryan and Iranian language families found today.

Significance: Reconstructing Proto-Indo-Iranian helps explain cognate patterns across its branches and informs theories about the historical movements of peoples across West, South, and Central Asia.