Sikhism, one of the major religions of India, was established by the ten Sikh Gurus, or masters, ranging over a period of 239 years, between the years 1469-1708. These ten Gurus were all highly enlightened souls who descended on earth with a mission to uplift the masses, bestowing on them happiness and well-being. They spread their message through the holy hymns called Shabads. Each of these Gurus added to and reinforced the message given by their predecessors, strengthening the very foundations of the religion, establishing it as a major world religion today. The ten Sikh Gurus are Guru Nanak, Guru Angad, Guru Amar Das, Guru Ram Das, Guru Arjan, Guru Hargobind, Guru Har Rai, Guru Har Krishan, Guru Tegh Bahadur and Guru Gobind Singh. Just before Guru Gobind Singh left for his heavenly abode, he made the Guru Granth Sahib, the holy book, the final and all-powerful Sikh Guru. This book is treated with the same reverence as an actual living God.