Guru Gobind Singh Ji (born Gobind Rai); 31 December 1666 - 21 October 1708) was the Tenth of the Eleven Sikh Gurus. Born in Patna, Bihar in India, he was also a Warrior, Poet and Philosopher. He succeeded his Father Guru Tegh Bahadur as the Leader of Sikhs at the young age of nine. He contributed much to Sikhism; notable was his contribution to the continual formalisation of the faith which the First Sikh Guru Ji Guru Nanak Dev Ji had founded, as a religion, in the 15th century. Guru Gobind Singh, the last of the living Sikh Gurus, initiated the Sikh Khalsa in 1699, passing the Guruship of the Sikhs to the Eleventh and and Eternal Guru of the Sikhs, the Guru Granth Sahib.