Proto-Indo-European (PIE) language is the hypothetical reconstruction of the modern ancestor of Indo-European languages, thus possibly pertaining to the root of around 445 spoken languages including Spanish, English, Hindi and Russian. However given the lack of any written record of this ‘mother’ language, PIE has been reconstructed by using methods of historical linguistics. Now since we brought up history, while there is no general consensus, PIE was possibly spoken by a group of ancient people residing in the Pontic–Caspian steppe area, north of Black Sea. But again (possibly) due to series of historical episodes (like migrations), many of the speakers became isolated from each other, thus causing divergence in the languages they spoke. The hypothetical date of this divergence pertains to around 3500 BC.