Khan Noonien Singh, or simply Khan, was a genetically-engineered Human and the most prominent tyrant of the late-20th century Eugenics Wars on Earth. Khan reappeared with a cadre of Augment followers in the 23rd century and became a notorious enemy of James T. Kirk.
Records of the period, including Khan's origins, are vague. He was the product of a secret selective-breeding and genetic engineering program, based on the eugenic philosophy that held improving the capabilities of a man improved the entire Human race. Augments produced by the program possessed physical strength and analytical capabilities superior to ordinary Humans, and were created from a variety of Earth's ethnic groups. Khan's background was suspected to be Sikh, from the northern region of India.