Khan (Nasta`liq: خان, Devanāgarī: ख़ान) is a surname and title of Asian origin. It can have one of several connotations, all related in some capacity to the title of Khan, which originated in Turkic and Central Asian traditions and was thereafter historically granted to Muslim rulers. Infiltration of the name from central Asia happened with the coming of Pashtuns into the sub-continent who used this name as a tile as well as a suffix to indicate their ethnic identity.[1] The later Turks and Mughal invaders also brought the name with them. Later Muslim Rajput rulers won the title Khan as a suffix upon accepting Islam.[2] Baloch tribes in Balochistan and in Sindh; Northern Iranian Turkic tribes; Subcontinental musicians; Sudhans of Kashmir; Krrals, Dhunds and miscellaneous tribes in northern Asia have all taken on this name without any historical or other justification. It is though generally used as a shorthand name for Pashtuns and Pathans throughout the South Asian subcontinent. In India it is referred to as name for Pathans as a tribe in the same way as Brahmin or other title among them. As a title, Khan has historically been used by the many Pashtuns in the Afghan territories of the current North West Frontier Province of Pakistan where the division of regions into Khanates has exited from early Muslim period e.g. the various Khanates in Swat, Hazara and Peshawar districts - notable Khan chiefs include the Bacha Khan family e.g. Khan Abdul Ghaffar Khan, the Swati Khans of Agror Valley and various others throughout the Pashtun belt. Some of the other Pashtun tribes adopted Malik as the chief's title especially nearer the border with Afghanistan.[3]

The British Raj continued the Mughal practice of awarding titles such as Khan Bahadur for Muslims and Rai Bahadur for Hindus. Khan is used as a family name for the descendants of people upon whom the British bestowed the titles Khan Sahib or Khan Bahadur.

Khan is also a last name found in Tatars, a Muslim Turkic speaking group, mostly in Russia. Also been known to be part with Genghis Khan's army. The name Khan has also been used by the Peoples of the Caucasus since the region has a history of Turkic and Mongolic rulers.

It is now a widespread surname in most countries of Central and South Asia. Khan is the surname of over 80,000 Britons, mostly British Asian, making it the 80th most common surname in the United Kingdom, and one of only a handful in the 100 most common surnames which are of neither British nor Irish origin.[4]