Khan is a historic Mongolic and Turkic title originating among nomadic tribes in the Central and Eastern Eurasian Steppe to refer to king. It first appears among the Rouran and then the Göktürks as a variant of khagan and implied a subordinate ruler. In the Seljuk Empire, it was the highest noble title, ranking above malik (king) and emir (prince). In the Mongol Empire it signified the ruler of a horde (ulus), while the ruler of all the Mongols was the khagan or great khan. The title subsequently declined in importance. During the Safavid and qajar dynasty it was the title of an army general high noble rank who ruling a province, and in Mughal India it was a high noble rank restricted to courtiers. After the downfall of the Mughals it was used promiscuously and became a surname. Khan and its female forms occur in many personal names, generally without any nobiliary of political relevance, although it remains a common part of noble names as well.

The proto-Mongols emerged from an area that had been inhabited by humans and predecessor hominin species as far back as 45,000 years ago during the Upper Paleolithic. The people there went through the Bronze and Iron Ages, forming tribal alliances, peopling, and coming into conflict with early polities in the Central Plain.