Khan (surname) – Wikipedia

Khan (/ k ɑː n /) is a surname deriving from the title khan, originating from the Central and Eastern Steppe during antiquity and popularized by Turkic dynasties in the rest of Asia during the medieval period. Used in the Rourans firstly, and also by the early rulers of Bulgaria, it was more widely spread by the Islamic chieftains in what is now Turkey, Iran, India, Pakistan, Afghanistan and …

https://en.wikipedia.org/wiki/Khan_%28surname%29