The contemporary Indo-Iranian languages form the largest sub-branch of Indo-European, with more than one billion speakers in total, stretching from Europe (Romani) and the Caucasus (Ossetian) to Xinjiang (Sarikoli) and East India or Bangladesh.
The oldest attested Indo-Iranian languages are Vedic Sanskrit (ancient Indian), Avestan and Old Persian (two ancient Iranian languages). But there are written instances of a fourth language in Northern Mesopotamia which is considered to be Indo-Aryan. They are attested in documents from the ancient empire of Mitanni and the Hittites of Anatolia.
- Indo-Aryan (221 languages)
- Iranian (87 languages)