Khan a title of dignity given to a high-ranking military officer of the Mughal or pre-Mughal time. The bureaucratic mansabdari system was basically a Turko-Mongol institution. The origin of the decimal basis of the mansabdari may be traced back to the early Muslim rulers who organised their armies on a decimal basis. The Turks introduced the decimal system in the Delhi Sultanate. Some ideas about the position of a Khan can be formed from the advice of Sultan Nasiruddin Mahmud bughra khan to his son Muizuddin Kaiqobad (sultan of Delhi, 1287-1290). Bughra Khan describes the army organisation to his son in the following manner: a sar-i-khail has ten horsemen under him, a Sipah Salar directs ten Sar-i-Khails, an amir has authority over ten Sipah Salars, a Malik has authority over ten Amirs and a Khan's forces contain at least those of ten Maliks. So a Khan appears to command one lac horsemen.
In the inscriptions of the Muslim sultans of Bengal there are gradations of titles like Khan, Khaqan/Malik as follows: Khan, Khan al-Muazzam, Khan al-Azam, Khan etc and Khaqan, Khaqan al-Muazzam, Khaqan al- Azam, Khaqan al-Azam al-Muazzam etc. [Abdul Karim]