Turkification, Turkization, or Turkicization (Türkleştirme) describes a shift whereby populations or places received or adopted Turkic attributes such as culture, language, history, or ethnicity. However, often this term is more narrowly applied to mean specifically Turkish rather than merely Turkic, therefore referring to the Ottoman Empire, and the Turkish nationalist policies of the Republic of Turkey toward ethnic minorities in Turkey. As the Turkic states developed and grew, there were many instances of this cultural shift. The earliest instance of Turkification took place in Central Asia, when by the 6th century AD migration of Turkic tribes from Inner Asia caused a language shift among the Iranian peoples of the area. Also, by the 8th century AD, Turkification of Kashgar was completed by Qarluq Turks, who also Islamized the population. Turkification of Anatolia occurred in the time of the Seljuk Empire and Sultanate of Rum, when Anatolia had been a diverse and largely Greek-speaking region after previously being Hellenized. Prior to the 20th century, Anatolian, Balkan, Caucasian, and Middle Eastern regions were said to undergo Ottomanization. "Turkification" started being used interchangeably with "Ottomanization" after the rise of Turkish nationalism in the 20th century. The term has been used in the Greek language since the 1300s or late-Byzantine era as "εκτουρκισμός", or "τούρκεμα". It literally means "becoming a Turk". Apart from persons, it may refer also to cities that were conquered by Turks or churches that were converted to mosques. It is more frequently used in the verb form "τουρκεύω" (turkify, become Muslim or Turk). By 750, the Turkification of Kashgar by the Qarluq Turks was underway. The Qarluqs were ancestors of the Karakhanids, who also islamized the population. The Iranian language of Khwarezm, a Central Asian oasis region, eventually died out as a result of Turkification. The current population of Central Asia is the result of the long and complex process that started since at least 1,400 years ago.