Middle Persian or Pahlavi, also known by its endonym Pārsīk or Pārsīg () in its later form, is a Western Middle Iranian language which became the literary language of the Sasanian Empire. For some time after the Sasanian collapse, Middle Persian continued to function as a prestige language. It descended from Old Persian, the language of the Achaemenid Empire and is the linguistic ancestor of Modern Persian, an official language of Iran, Afghanistan (Dari) and Tajikistan (Tajik). Name "Middle Iranian" is the name given to the middle stage of development of the numerous Iranian languages and dialects. The middle stage of the Iranian languages begins around 450 BCE and ends around 650 CE. One of those Middle Iranian languages is Middle Persian, i.e. the middle stage of the language of the Persians, an Iranian people of Persia proper, which lies in the south-western highlands on the border with Babylonia. The Persians called their language Parsik, meaning "Persian". Another Middle Iranian language was Parthian, i.e. the language of the northwestern Iranian peoples of Parthia proper, which lies along the southern/south-eastern edge of the Caspian sea and is adjacent to the boundary between western and eastern Iranian languages. The Parthians called their language Parthawik, meaning "Parthian". Via regular sound changes Parthawik became Pahlawik, from which the word 'Pahlavi' eventually evolved. The -ik in parsik and parthawik was a regular Middle Iranian appurtenant suffix for "pertaining to". The New Persian equivalent of -ik is -i. When the Arsacids (who were Parthians) came to power in the 3rd-century BCE, they inherited the use of written Greek (from the successors of Alexander the Great) as the language of government. Under the cultural influence of the Greeks (Hellenization), some Middle Iranian languages, such as Bactrian, also had begun to be written in Greek script. But yet other Middle Iranian languages began to be written in a script derived from Aramaic. This occurred primarily because written Aramaic had previously been the written language of government of the former Achaemenids, and the government scribes had carried that practice all over the empire. This practice had led to others adopting Imperial Aramaic as the language of communications, both between Iranians and non-Iranians, as well as between Iranians. The transition from Imperial Aramaic to Middle Iranian took place very slowly, with a slow increase of more and more Iranian words so that Aramaic with Iranian elements gradually changed into Iranian