The latter two names refer to its position beyond the River Oxus when approached from the south, emphasizing Turkestan's long-standing relationship with Iran, the Persian Empires, and the Umayyad and Abbasid Caliphates.
Oghuz Turks (also known as Turkmens), Kyrgyzs, Uzbeks, Kazakhs, Khazars, Uyghurs, and Hazaras are some of the Turkic inhabitants of the region who, as history progressed, have spread further into Eurasia forming such Turkic nations as Turkey, and subnational regions like Tatarstan in Russia and Crimea in Ukraine.
[5][4] According to ethnographer Dávid Somfai Kara, prior to the Russian conquest, Turkestan historically referred only to the western portion of Central Asia:[6] The Eastern part of Central Asia (inhabited by nomads of the Tien Shan Mountains and settled peoples of the Tarim Basin) was called Moghulistan (“Mongol land”).
[5][7] In 1969, a Turfanian document from 639 CE was found in the Astana district of Turpan, which recorded Sogdian sale contract of a female slave from the period of the Gaochang kingdom under the rule of Qu clan and mentioned the Sogdian word "twrkstn", which may have referred to the lands to the east and north of Syr Darya in the realm of the First Turkic Khaganate.
[9][10] The history of the Central Asian region that was later called Turkestan dates back to at least the third millennium BC.
With the dissolution of the Huns' Empire, Chinese rulers took over Eastern Central Asia, which was centuries later also called Turkestan.
[11] The entire territory was held at various times by Turkic forces, such as the Göktürks, until the conquest by Genghis Khan and the Mongols in 1220.
[11] The eastern portion of Turkestan was also called Moghulistan and continued to be ruled by descendants of Genghis Khan.
The Chinese emperor, together with the rulers of the Turks, Arabs, India and the Byzantine Romans, were known to Islamic writers as the world's "five great kings".