According to the Encyclopaedia of Islam, "Khatun [is] a title of Sogdian origin borne by the wives and female relatives of the Göktürks and subsequent Turkish rulers.
De Nicola states that prior to the spread of the Mongols across Central Asia, Khatun meant 'lady' or 'noblewoman' and is found in broad usage in medieval Persian and Arabic texts.
[2] Peter Benjamin Golden observed that the title qatun appeared among the Göktürks as the title for the khagan's wife and was borrowed from Sogdian xwāten "wife of the ruler"[3] Earlier, British Orientalist Gerard Clauson (1891–1974) defined xa:tun as "'lady' and the like" and says there is "no reasonable doubt that it is taken from Sogdian xwt'yn (xwatēn), in Sogdian xwt'y ('lord, ruler') and xwt'yn 'lord's or ruler's wife'), "which is precisely the meaning of xa:tun in the early period.
"[4] In Uzbek, the language spoken in modern-day Bukhara, in Uzbekistan, the word is spelled xotin and has come to simply refer to any woman.
[5] Valide Hatun was the title held by the "legal mother" of a ruling Sultan of the Ottoman Empire before the 16th century.