A monotheistic religion founded in the Punjab in the 15th century by Guru Nanak. It combines elements of Hinduism and Islam, accepting the Hindu concepts of karma and reincarnation but rejecting the caste system, and has one sacred scripture, the Adi Granth. The tenth and last of the series of gurus, Gobind Singh, prescribed the distinctive outward forms (the so-called five Ks)—long hair (to be covered by a turban) and uncut beard (kesh), comb (kangha), short sword (kirpan), steel bangle (kara), and short trousers for horse-riding (kaccha). Originating as a religion, Sikhism became a militant political movement in the Punjab, where most of the world’s 25 million Sikhs live.